Use std::foo_t rather than std::foo in LLVM.

Summary: C++14 migration. No functional change.

Reviewers: bkramer, JDevlieghere, lebedev.ri

Subscribers: MatzeB, hiraditya, jkorous, dexonsmith, arphaman, kadircet, lebedev.ri, usaxena95, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D74384

include/llvm/ADT/APFloat.h

@@ -853,8 +853,8 @@ public:
   APFloat(const fltSemantics &Semantics) : U(Semantics) {}
   APFloat(const fltSemantics &Semantics, StringRef S);
   APFloat(const fltSemantics &Semantics, integerPart I) : U(Semantics, I) {}
-  template <typename T, typename = typename std::enable_if<
+  template <typename T,
-                            std::is_floating_point<T>::value>::type>
+            typename = std::enable_if_t<std::is_floating_point<T>::value>>
   APFloat(const fltSemantics &Semantics, T V) = delete;
   // TODO: Remove this constructor. This isn't faster than the first one.
   APFloat(const fltSemantics &Semantics, uninitializedTag)

include/llvm/ADT/AllocatorList.h

@@ -110,8 +110,8 @@ private:
 
     template <class OtherValueT, class OtherIteratorBase>
     IteratorImpl(const IteratorImpl<OtherValueT, OtherIteratorBase> &X,
-                 typename std::enable_if<std::is_convertible<
+                 std::enable_if_t<std::is_convertible<
-                     OtherIteratorBase, IteratorBase>::value>::type * = nullptr)
+                     OtherIteratorBase, IteratorBase>::value> * = nullptr)
         : base_type(X.wrapped()) {}
 
     ~IteratorImpl() = default;

include/llvm/ADT/Any.h

@@ -59,26 +59,26 @@ public:
   // When T is Any or T is not copy-constructible we need to explicitly disable
   // the forwarding constructor so that the copy constructor gets selected
   // instead.
-  template <
+  template <typename T,
-      typename T,
+            std::enable_if_t<
-      typename std::enable_if<
+                llvm::conjunction<
-          llvm::conjunction<
+                    llvm::negation<std::is_same<std::decay_t<T>, Any>>,
-              llvm::negation<std::is_same<typename std::decay<T>::type, Any>>,
+                    // We also disable this overload when an `Any` object can be
-              // We also disable this overload when an `Any` object can be
+                    // converted to the parameter type because in that case,
-              // converted to the parameter type because in that case, this
+                    // this constructor may combine with that conversion during
-              // constructor may combine with that conversion during overload
+                    // overload resolution for determining copy
-              // resolution for determining copy constructibility, and then
+                    // constructibility, and then when we try to determine copy
-              // when we try to determine copy constructibility below we may
+                    // constructibility below we may infinitely recurse. This is
-              // infinitely recurse. This is being evaluated by the standards
+                    // being evaluated by the standards committee as a potential
-              // committee as a potential DR in `std::any` as well, but we're
+                    // DR in `std::any` as well, but we're going ahead and
-              // going ahead and adopting it to work-around usage of `Any` with
+                    // adopting it to work-around usage of `Any` with types that
-              // types that need to be implicitly convertible from an `Any`.
+                    // need to be implicitly convertible from an `Any`.
-              llvm::negation<std::is_convertible<Any, typename std::decay<T>::type>>,
+                    llvm::negation<std::is_convertible<Any, std::decay_t<T>>>,
-              std::is_copy_constructible<typename std::decay<T>::type>>::value,
+                    std::is_copy_constructible<std::decay<T>>>::value,
-          int>::type = 0>
+                int> = 0>
   Any(T &&Value) {
-    using U = typename std::decay<T>::type;
+    Storage =
-    Storage = std::make_unique<StorageImpl<U>>(std::forward<T>(Value));
+        std::make_unique<StorageImpl<std::decay_t<T>>>(std::forward<T>(Value));
   }
 
   Any(Any &&Other) : Storage(std::move(Other.Storage)) {}
@@ -114,32 +114,27 @@ template <typename T> const char Any::TypeId<T>::Id = 0;
 template <typename T> bool any_isa(const Any &Value) {
   if (!Value.Storage)
     return false;
-  using U =
+  return Value.Storage->id() ==
-      typename std::remove_cv<typename std::remove_reference<T>::type>::type;
+         &Any::TypeId<std::remove_cv_t<std::remove_reference_t<T>>>::Id;
-  return Value.Storage->id() == &Any::TypeId<U>::Id;
 }
 
 template <class T> T any_cast(const Any &Value) {
-  using U =
+  return static_cast<T>(
-      typename std::remove_cv<typename std::remove_reference<T>::type>::type;
+      *any_cast<std::remove_cv_t<std::remove_reference_t<T>>>(&Value));
-  return static_cast<T>(*any_cast<U>(&Value));
 }
 
 template <class T> T any_cast(Any &Value) {
-  using U =
+  return static_cast<T>(
-      typename std::remove_cv<typename std::remove_reference<T>::type>::type;
+      *any_cast<std::remove_cv_t<std::remove_reference_t<T>>>(&Value));
-  return static_cast<T>(*any_cast<U>(&Value));
 }
 
 template <class T> T any_cast(Any &&Value) {
-  using U =
+  return static_cast<T>(std::move(
-      typename std::remove_cv<typename std::remove_reference<T>::type>::type;
+      *any_cast<std::remove_cv_t<std::remove_reference_t<T>>>(&Value)));
-  return static_cast<T>(std::move(*any_cast<U>(&Value)));
 }
 
 template <class T> const T *any_cast(const Any *Value) {
-  using U =
+  using U = std::remove_cv_t<std::remove_reference_t<T>>;
-      typename std::remove_cv<typename std::remove_reference<T>::type>::type;
   assert(Value && any_isa<T>(*Value) && "Bad any cast!");
   if (!Value || !any_isa<U>(*Value))
     return nullptr;
@@ -147,7 +142,7 @@ template <class T> const T *any_cast(const Any *Value) {
 }
 
 template <class T> T *any_cast(Any *Value) {
-  using U = typename std::decay<T>::type;
+  using U = std::decay_t<T>;
   assert(Value && any_isa<U>(*Value) && "Bad any cast!");
   if (!Value || !any_isa<U>(*Value))
     return nullptr;

include/llvm/ADT/ArrayRef.h

@@ -114,30 +114,28 @@ namespace llvm {
     /// Construct an ArrayRef<const T*> from ArrayRef<T*>. This uses SFINAE to
     /// ensure that only ArrayRefs of pointers can be converted.
     template <typename U>
-    ArrayRef(
+    ArrayRef(const ArrayRef<U *> &A,
-        const ArrayRef<U *> &A,
+             std::enable_if_t<std::is_convertible<U *const *, T const *>::value>
-        typename std::enable_if<
+                 * = nullptr)
-           std::is_convertible<U *const *, T const *>::value>::type * = nullptr)
+        : Data(A.data()), Length(A.size()) {}
-      : Data(A.data()), Length(A.size()) {}
 
     /// Construct an ArrayRef<const T*> from a SmallVector<T*>. This is
     /// templated in order to avoid instantiating SmallVectorTemplateCommon<T>
     /// whenever we copy-construct an ArrayRef.
-    template<typename U, typename DummyT>
+    template <typename U, typename DummyT>
     /*implicit*/ ArrayRef(
-      const SmallVectorTemplateCommon<U *, DummyT> &Vec,
+        const SmallVectorTemplateCommon<U *, DummyT> &Vec,
-      typename std::enable_if<
+        std::enable_if_t<std::is_convertible<U *const *, T const *>::value> * =
-          std::is_convertible<U *const *, T const *>::value>::type * = nullptr)
+            nullptr)
-      : Data(Vec.data()), Length(Vec.size()) {
+        : Data(Vec.data()), Length(Vec.size()) {}
-    }
 
     /// Construct an ArrayRef<const T*> from std::vector<T*>. This uses SFINAE
     /// to ensure that only vectors of pointers can be converted.
-    template<typename U, typename A>
+    template <typename U, typename A>
     ArrayRef(const std::vector<U *, A> &Vec,
-             typename std::enable_if<
+             std::enable_if_t<std::is_convertible<U *const *, T const *>::value>
-                 std::is_convertible<U *const *, T const *>::value>::type* = 0)
+                 * = 0)
-      : Data(Vec.data()), Length(Vec.size()) {}
+        : Data(Vec.data()), Length(Vec.size()) {}
 
     /// @}
     /// @name Simple Operations
@@ -256,7 +254,7 @@ namespace llvm {
     /// The declaration here is extra complicated so that "arrayRef = {}"
     /// continues to select the move assignment operator.
     template <typename U>
-    typename std::enable_if<std::is_same<U, T>::value, ArrayRef<T>>::type &
+    std::enable_if_t<std::is_same<U, T>::value, ArrayRef<T>> &
     operator=(U &&Temporary) = delete;
 
     /// Disallow accidental assignment from a temporary.
@@ -264,7 +262,7 @@ namespace llvm {
     /// The declaration here is extra complicated so that "arrayRef = {}"
     /// continues to select the move assignment operator.
     template <typename U>
-    typename std::enable_if<std::is_same<U, T>::value, ArrayRef<T>>::type &
+    std::enable_if_t<std::is_same<U, T>::value, ArrayRef<T>> &
     operator=(std::initializer_list<U>) = delete;
 
     /// @}

include/llvm/ADT/BitmaskEnum.h

@@ -71,49 +71,45 @@ struct is_bitmask_enum : std::false_type {};
 
 template <typename E>
 struct is_bitmask_enum<
-    E, typename std::enable_if<sizeof(E::LLVM_BITMASK_LARGEST_ENUMERATOR) >=
+    E, std::enable_if_t<sizeof(E::LLVM_BITMASK_LARGEST_ENUMERATOR) >= 0>>
-                               0>::type> : std::true_type {};
+    : std::true_type {};
 namespace BitmaskEnumDetail {
 
 /// Get a bitmask with 1s in all places up to the high-order bit of E's largest
 /// value.
-template <typename E> typename std::underlying_type<E>::type Mask() {
+template <typename E> std::underlying_type_t<E> Mask() {
   // On overflow, NextPowerOf2 returns zero with the type uint64_t, so
   // subtracting 1 gives us the mask with all bits set, like we want.
-  return NextPowerOf2(static_cast<typename std::underlying_type<E>::type>(
+  return NextPowerOf2(static_cast<std::underlying_type_t<E>>(
              E::LLVM_BITMASK_LARGEST_ENUMERATOR)) -
          1;
 }
 
 /// Check that Val is in range for E, and return Val cast to E's underlying
 /// type.
-template <typename E> typename std::underlying_type<E>::type Underlying(E Val) {
+template <typename E> std::underlying_type_t<E> Underlying(E Val) {
-  auto U = static_cast<typename std::underlying_type<E>::type>(Val);
+  auto U = static_cast<std::underlying_type_t<E>>(Val);
   assert(U >= 0 && "Negative enum values are not allowed.");
   assert(U <= Mask<E>() && "Enum value too large (or largest val too small?)");
   return U;
 }
 
-template <typename E,
+template <typename E, typename = std::enable_if_t<is_bitmask_enum<E>::value>>
-          typename = typename std::enable_if<is_bitmask_enum<E>::value>::type>
 E operator~(E Val) {
   return static_cast<E>(~Underlying(Val) & Mask<E>());
 }
 
-template <typename E,
+template <typename E, typename = std::enable_if_t<is_bitmask_enum<E>::value>>
-          typename = typename std::enable_if<is_bitmask_enum<E>::value>::type>
 E operator|(E LHS, E RHS) {
   return static_cast<E>(Underlying(LHS) | Underlying(RHS));
 }
 
-template <typename E,
+template <typename E, typename = std::enable_if_t<is_bitmask_enum<E>::value>>
-          typename = typename std::enable_if<is_bitmask_enum<E>::value>::type>
 E operator&(E LHS, E RHS) {
   return static_cast<E>(Underlying(LHS) & Underlying(RHS));
 }
 
-template <typename E,
+template <typename E, typename = std::enable_if_t<is_bitmask_enum<E>::value>>
-          typename = typename std::enable_if<is_bitmask_enum<E>::value>::type>
 E operator^(E LHS, E RHS) {
   return static_cast<E>(Underlying(LHS) ^ Underlying(RHS));
 }
@@ -121,22 +117,19 @@ E operator^(E LHS, E RHS) {
 // |=, &=, and ^= return a reference to LHS, to match the behavior of the
 // operators on builtin types.
 
-template <typename E,
+template <typename E, typename = std::enable_if_t<is_bitmask_enum<E>::value>>
-          typename = typename std::enable_if<is_bitmask_enum<E>::value>::type>
 E &operator|=(E &LHS, E RHS) {
   LHS = LHS | RHS;
   return LHS;
 }
 
-template <typename E,
+template <typename E, typename = std::enable_if_t<is_bitmask_enum<E>::value>>
-          typename = typename std::enable_if<is_bitmask_enum<E>::value>::type>
 E &operator&=(E &LHS, E RHS) {
   LHS = LHS & RHS;
   return LHS;
 }
 
-template <typename E,
+template <typename E, typename = std::enable_if_t<is_bitmask_enum<E>::value>>
-          typename = typename std::enable_if<is_bitmask_enum<E>::value>::type>
 E &operator^=(E &LHS, E RHS) {
   LHS = LHS ^ RHS;
   return LHS;

include/llvm/ADT/DenseMap.h

@@ -1194,7 +1194,7 @@ public:
   // for const iterator destinations so it doesn't end up as a user defined copy
   // constructor.
   template <bool IsConstSrc,
-            typename = typename std::enable_if<!IsConstSrc && IsConst>::type>
+            typename = std::enable_if_t<!IsConstSrc && IsConst>>
   DenseMapIterator(
       const DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, IsConstSrc> &I)
       : DebugEpochBase::HandleBase(I), Ptr(I.Ptr), End(I.End) {}

include/llvm/ADT/Hashing.h

@@ -101,8 +101,7 @@ public:
 /// differing argument types even if they would implicit promote to a common
 /// type without changing the value.
 template <typename T>
-typename std::enable_if<is_integral_or_enum<T>::value, hash_code>::type
+std::enable_if_t<is_integral_or_enum<T>::value, hash_code> hash_value(T value);
-hash_value(T value);
 
 /// Compute a hash_code for a pointer's address.
 ///
@@ -360,7 +359,7 @@ template <typename T, typename U> struct is_hashable_data<std::pair<T, U> >
 /// Helper to get the hashable data representation for a type.
 /// This variant is enabled when the type itself can be used.
 template <typename T>
-typename std::enable_if<is_hashable_data<T>::value, T>::type
+std::enable_if_t<is_hashable_data<T>::value, T>
 get_hashable_data(const T &value) {
   return value;
 }
@@ -368,7 +367,7 @@ get_hashable_data(const T &value) {
 /// This variant is enabled when we must first call hash_value and use the
 /// result as our data.
 template <typename T>
-typename std::enable_if<!is_hashable_data<T>::value, size_t>::type
+std::enable_if_t<!is_hashable_data<T>::value, size_t>
 get_hashable_data(const T &value) {
   using ::llvm::hash_value;
   return hash_value(value);
@@ -442,7 +441,7 @@ hash_code hash_combine_range_impl(InputIteratorT first, InputIteratorT last) {
 /// are stored in contiguous memory, this routine avoids copying each value
 /// and directly reads from the underlying memory.
 template <typename ValueT>
-typename std::enable_if<is_hashable_data<ValueT>::value, hash_code>::type
+std::enable_if_t<is_hashable_data<ValueT>::value, hash_code>
 hash_combine_range_impl(ValueT *first, ValueT *last) {
   const uint64_t seed = get_execution_seed();
   const char *s_begin = reinterpret_cast<const char *>(first);
@@ -627,8 +626,7 @@ inline hash_code hash_integer_value(uint64_t value) {
 // Declared and documented above, but defined here so that any of the hashing
 // infrastructure is available.
 template <typename T>
-typename std::enable_if<is_integral_or_enum<T>::value, hash_code>::type
+std::enable_if_t<is_integral_or_enum<T>::value, hash_code> hash_value(T value) {
-hash_value(T value) {
   return ::llvm::hashing::detail::hash_integer_value(
       static_cast<uint64_t>(value));
 }

include/llvm/ADT/PriorityWorklist.h

@@ -110,7 +110,7 @@ public:
 
   /// Insert a sequence of new elements into the PriorityWorklist.
   template <typename SequenceT>
-  typename std::enable_if<!std::is_convertible<SequenceT, T>::value>::type
+  std::enable_if_t<!std::is_convertible<SequenceT, T>::value>
   insert(SequenceT &&Input) {
     if (std::begin(Input) == std::end(Input))
       // Nothing to do for an empty input sequence.

include/llvm/ADT/STLExtras.h

@@ -115,9 +115,8 @@ public:
 
   template <typename Callable>
   function_ref(Callable &&callable,
-               typename std::enable_if<
+               std::enable_if_t<!std::is_same<std::remove_reference_t<Callable>,
-                   !std::is_same<typename std::remove_reference<Callable>::type,
+                                              function_ref>::value> * = nullptr)
-                                 function_ref>::value>::type * = nullptr)
       : callback(callback_fn<typename std::remove_reference<Callable>::type>),
         callable(reinterpret_cast<intptr_t>(&callable)) {}
 
@@ -254,9 +253,8 @@ struct has_rbegin : has_rbegin_impl<typename std::remove_reference<Ty>::type> {
 // Returns an iterator_range over the given container which iterates in reverse.
 // Note that the container must have rbegin()/rend() methods for this to work.
 template <typename ContainerTy>
-auto reverse(
+auto reverse(ContainerTy &&C,
-    ContainerTy &&C,
+             std::enable_if_t<has_rbegin<ContainerTy>::value> * = nullptr) {
-    typename std::enable_if<has_rbegin<ContainerTy>::value>::type * = nullptr) {
   return make_range(C.rbegin(), C.rend());
 }
 
@@ -271,8 +269,7 @@ std::reverse_iterator<IteratorTy> make_reverse_iterator(IteratorTy It) {
 // bidirectional iterators for this to work.
 template <typename ContainerTy>
 auto reverse(ContainerTy &&C,
-             typename std::enable_if<!has_rbegin<ContainerTy>::value>::type * =
+             std::enable_if_t<!has_rbegin<ContainerTy>::value> * = nullptr) {
-                 nullptr) {
   return make_range(llvm::make_reverse_iterator(std::end(C)),
                     llvm::make_reverse_iterator(std::begin(C)));
 }
@@ -1148,11 +1145,11 @@ void DeleteContainerSeconds(Container &C) {
 /// Get the size of a range. This is a wrapper function around std::distance
 /// which is only enabled when the operation is O(1).
 template <typename R>
-auto size(R &&Range, typename std::enable_if<
+auto size(R &&Range,
-                         std::is_same<typename std::iterator_traits<decltype(
+          std::enable_if_t<std::is_same<typename std::iterator_traits<decltype(
-                                          Range.begin())>::iterator_category,
+                                            Range.begin())>::iterator_category,
-                                      std::random_access_iterator_tag>::value,
+                                        std::random_access_iterator_tag>::value,
-                         void>::type * = nullptr) {
+                           void> * = nullptr) {
   return std::distance(Range.begin(), Range.end());
 }
 
@@ -1516,12 +1513,11 @@ decltype(auto) apply_tuple(F &&f, Tuple &&t) {
 template <typename IterTy>
 bool hasNItems(
     IterTy &&Begin, IterTy &&End, unsigned N,
-    typename std::enable_if<
+    std::enable_if_t<
-        !std::is_same<
+        !std::is_same<typename std::iterator_traits<std::remove_reference_t<
-            typename std::iterator_traits<typename std::remove_reference<
+                          decltype(Begin)>>::iterator_category,
-                decltype(Begin)>::type>::iterator_category,
+                      std::random_access_iterator_tag>::value,
-            std::random_access_iterator_tag>::value,
+        void> * = nullptr) {
-        void>::type * = nullptr) {
   for (; N; --N, ++Begin)
     if (Begin == End)
       return false; // Too few.
@@ -1533,12 +1529,11 @@ bool hasNItems(
 template <typename IterTy>
 bool hasNItemsOrMore(
     IterTy &&Begin, IterTy &&End, unsigned N,
-    typename std::enable_if<
+    std::enable_if_t<
-        !std::is_same<
+        !std::is_same<typename std::iterator_traits<std::remove_reference_t<
-            typename std::iterator_traits<typename std::remove_reference<
+                          decltype(Begin)>>::iterator_category,
-                decltype(Begin)>::type>::iterator_category,
+                      std::random_access_iterator_tag>::value,
-            std::random_access_iterator_tag>::value,
+        void> * = nullptr) {
-        void>::type * = nullptr) {
   for (; N; --N, ++Begin)
     if (Begin == End)
       return false; // Too few.

include/llvm/ADT/SmallVector.h

@@ -284,8 +284,8 @@ protected:
   template <typename T1, typename T2>
   static void uninitialized_copy(
       T1 *I, T1 *E, T2 *Dest,
-      typename std::enable_if<std::is_same<typename std::remove_const<T1>::type,
+      std::enable_if_t<std::is_same<typename std::remove_const<T1>::type,
-                                           T2>::value>::type * = nullptr) {
+                                    T2>::value> * = nullptr) {
     // Use memcpy for PODs iterated by pointers (which includes SmallVector
     // iterators): std::uninitialized_copy optimizes to memmove, but we can
     // use memcpy here. Note that I and E are iterators and thus might be
@@ -381,9 +381,9 @@ public:
 
   /// Add the specified range to the end of the SmallVector.
   template <typename in_iter,
-            typename = typename std::enable_if<std::is_convertible<
+            typename = std::enable_if_t<std::is_convertible<
                 typename std::iterator_traits<in_iter>::iterator_category,
-                std::input_iterator_tag>::value>::type>
+                std::input_iterator_tag>::value>>
   void append(in_iter in_start, in_iter in_end) {
     size_type NumInputs = std::distance(in_start, in_end);
     if (NumInputs > this->capacity() - this->size())
@@ -418,9 +418,9 @@ public:
   }
 
   template <typename in_iter,
-            typename = typename std::enable_if<std::is_convertible<
+            typename = std::enable_if_t<std::is_convertible<
                 typename std::iterator_traits<in_iter>::iterator_category,
-                std::input_iterator_tag>::value>::type>
+                std::input_iterator_tag>::value>>
   void assign(in_iter in_start, in_iter in_end) {
     clear();
     append(in_start, in_end);
@@ -575,9 +575,9 @@ public:
   }
 
   template <typename ItTy,
-            typename = typename std::enable_if<std::is_convertible<
+            typename = std::enable_if_t<std::is_convertible<
                 typename std::iterator_traits<ItTy>::iterator_category,
-                std::input_iterator_tag>::value>::type>
+                std::input_iterator_tag>::value>>
   iterator insert(iterator I, ItTy From, ItTy To) {
     // Convert iterator to elt# to avoid invalidating iterator when we reserve()
     size_t InsertElt = I - this->begin();
@@ -849,9 +849,9 @@ public:
   }
 
   template <typename ItTy,
-            typename = typename std::enable_if<std::is_convertible<
+            typename = std::enable_if_t<std::is_convertible<
                 typename std::iterator_traits<ItTy>::iterator_category,
-                std::input_iterator_tag>::value>::type>
+                std::input_iterator_tag>::value>>
   SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(N) {
     this->append(S, E);
   }

include/llvm/ADT/StringRef.h

@@ -265,8 +265,7 @@ namespace llvm {
     /// The declaration here is extra complicated so that `stringRef = {}`
     /// and `stringRef = "abc"` continue to select the move assignment operator.
     template <typename T>
-    typename std::enable_if<std::is_same<T, std::string>::value,
+    std::enable_if_t<std::is_same<T, std::string>::value, StringRef> &
-                            StringRef>::type &
     operator=(T &&Str) = delete;
 
     /// @}
@@ -508,7 +507,7 @@ namespace llvm {
     /// this returns true to signify the error.  The string is considered
     /// erroneous if empty or if it overflows T.
     template <typename T>
-    typename std::enable_if<std::numeric_limits<T>::is_signed, bool>::type
+    std::enable_if_t<std::numeric_limits<T>::is_signed, bool>
     getAsInteger(unsigned Radix, T &Result) const {
       long long LLVal;
       if (getAsSignedInteger(*this, Radix, LLVal) ||
@@ -519,7 +518,7 @@ namespace llvm {
     }
 
     template <typename T>
-    typename std::enable_if<!std::numeric_limits<T>::is_signed, bool>::type
+    std::enable_if_t<!std::numeric_limits<T>::is_signed, bool>
     getAsInteger(unsigned Radix, T &Result) const {
       unsigned long long ULLVal;
       // The additional cast to unsigned long long is required to avoid the
@@ -542,7 +541,7 @@ namespace llvm {
     /// The portion of the string representing the discovered numeric value
     /// is removed from the beginning of the string.
     template <typename T>
-    typename std::enable_if<std::numeric_limits<T>::is_signed, bool>::type
+    std::enable_if_t<std::numeric_limits<T>::is_signed, bool>
     consumeInteger(unsigned Radix, T &Result) {
       long long LLVal;
       if (consumeSignedInteger(*this, Radix, LLVal) ||
@@ -553,7 +552,7 @@ namespace llvm {
     }
 
     template <typename T>
-    typename std::enable_if<!std::numeric_limits<T>::is_signed, bool>::type
+    std::enable_if_t<!std::numeric_limits<T>::is_signed, bool>
     consumeInteger(unsigned Radix, T &Result) {
       unsigned long long ULLVal;
       if (consumeUnsignedInteger(*this, Radix, ULLVal) ||

include/llvm/ADT/TinyPtrVector.h

@@ -152,10 +152,10 @@ public:
   }
 
   // Implicit conversion to ArrayRef<U> if EltTy* implicitly converts to U*.
-  template<typename U,
+  template <
-           typename std::enable_if<
+      typename U,
-               std::is_convertible<ArrayRef<EltTy>, ArrayRef<U>>::value,
+      std::enable_if_t<std::is_convertible<ArrayRef<EltTy>, ArrayRef<U>>::value,
-               bool>::type = false>
+                       bool> = false>
   operator ArrayRef<U>() const {
     return operator ArrayRef<EltTy>();
   }

include/llvm/ADT/ilist_iterator.h

@@ -88,15 +88,14 @@ public:
   // This is templated so that we can allow constructing a const iterator from
   // a nonconst iterator...
   template <bool RHSIsConst>
-  ilist_iterator(
+  ilist_iterator(const ilist_iterator<OptionsT, IsReverse, RHSIsConst> &RHS,
-      const ilist_iterator<OptionsT, IsReverse, RHSIsConst> &RHS,
+                 std::enable_if_t<IsConst || !RHSIsConst, void *> = nullptr)
-      typename std::enable_if<IsConst || !RHSIsConst, void *>::type = nullptr)
       : NodePtr(RHS.NodePtr) {}
 
   // This is templated so that we can allow assigning to a const iterator from
   // a nonconst iterator...
   template <bool RHSIsConst>
-  typename std::enable_if<IsConst || !RHSIsConst, ilist_iterator &>::type
+  std::enable_if_t<IsConst || !RHSIsConst, ilist_iterator &>
   operator=(const ilist_iterator<OptionsT, IsReverse, RHSIsConst> &RHS) {
     NodePtr = RHS.NodePtr;
     return *this;

include/llvm/ADT/iterator.h

@@ -194,14 +194,14 @@ template <
     typename T = typename std::iterator_traits<WrappedIteratorT>::value_type,
     typename DifferenceTypeT =
         typename std::iterator_traits<WrappedIteratorT>::difference_type,
-    typename PointerT = typename std::conditional<
+    typename PointerT = std::conditional_t<
         std::is_same<T, typename std::iterator_traits<
                             WrappedIteratorT>::value_type>::value,
-        typename std::iterator_traits<WrappedIteratorT>::pointer, T *>::type,
+        typename std::iterator_traits<WrappedIteratorT>::pointer, T *>,
-    typename ReferenceT = typename std::conditional<
+    typename ReferenceT = std::conditional_t<
         std::is_same<T, typename std::iterator_traits<
                             WrappedIteratorT>::value_type>::value,
-        typename std::iterator_traits<WrappedIteratorT>::reference, T &>::type>
+        typename std::iterator_traits<WrappedIteratorT>::reference, T &>>
 class iterator_adaptor_base
     : public iterator_facade_base<DerivedT, IteratorCategoryT, T,
                                   DifferenceTypeT, PointerT, ReferenceT> {
@@ -281,8 +281,8 @@ public:
 ///   using iterator = pointee_iterator<SmallVectorImpl<T *>::iterator>;
 /// \endcode
 template <typename WrappedIteratorT,
-          typename T = typename std::remove_reference<
+          typename T = std::remove_reference_t<decltype(
-              decltype(**std::declval<WrappedIteratorT>())>::type>
+              **std::declval<WrappedIteratorT>())>>
 struct pointee_iterator
     : iterator_adaptor_base<
           pointee_iterator<WrappedIteratorT, T>, WrappedIteratorT,
@@ -334,9 +334,11 @@ make_pointer_range(RangeT &&Range) {
 }
 
 template <typename WrappedIteratorT,
-          typename T1 = typename std::remove_reference<decltype(**std::declval<WrappedIteratorT>())>::type,
+          typename T1 = std::remove_reference_t<decltype(
-          typename T2 = typename std::add_pointer<T1>::type>
+              **std::declval<WrappedIteratorT>())>,
-using raw_pointer_iterator = pointer_iterator<pointee_iterator<WrappedIteratorT, T1>, T2>;
+          typename T2 = std::add_pointer_t<T1>>
+using raw_pointer_iterator =
+    pointer_iterator<pointee_iterator<WrappedIteratorT, T1>, T2>;
 
 // Wrapper iterator over iterator ItType, adding DataRef to the type of ItType,
 // to create NodeRef = std::pair<InnerTypeOfItType, DataRef>.

include/llvm/Analysis/RegionInfo.h

@@ -574,10 +574,9 @@ public:
   template <bool IsConst>
   class block_iterator_wrapper
       : public df_iterator<
-            typename std::conditional<IsConst, const BlockT, BlockT>::type *> {
+            std::conditional_t<IsConst, const BlockT, BlockT> *> {
     using super =
-        df_iterator<
+        df_iterator<std::conditional_t<IsConst, const BlockT, BlockT> *>;
-            typename std::conditional<IsConst, const BlockT, BlockT>::type *>;
 
   public:
     using Self = block_iterator_wrapper<IsConst>;

include/llvm/Analysis/RegionInfoImpl.h

@@ -724,7 +724,7 @@ void RegionInfoBase<Tr>::findRegionsWithEntry(BlockT *entry,
 
 template <class Tr>
 void RegionInfoBase<Tr>::scanForRegions(FuncT &F, BBtoBBMap *ShortCut) {
-  using FuncPtrT = typename std::add_pointer<FuncT>::type;
+  using FuncPtrT = std::add_pointer_t<FuncT>;
 
   BlockT *entry = GraphTraits<FuncPtrT>::getEntryNode(&F);
   DomTreeNodeT *N = DT->getNode(entry);
@@ -912,7 +912,7 @@ RegionInfoBase<Tr>::getCommonRegion(SmallVectorImpl<BlockT *> &BBs) const {
 
 template <class Tr>
 void RegionInfoBase<Tr>::calculate(FuncT &F) {
-  using FuncPtrT = typename std::add_pointer<FuncT>::type;
+  using FuncPtrT = std::add_pointer_t<FuncT>;
 
   // ShortCut a function where for every BB the exit of the largest region
   // starting with BB is stored. These regions can be threated as single BBS.

include/llvm/BinaryFormat/Dwarf.h

@@ -672,8 +672,7 @@ template <> struct EnumTraits<LineNumberOps> : public std::true_type {
 /// dumping functions above, these format unknown enumerator values as
 /// DW_TYPE_unknown_1234 (e.g. DW_TAG_unknown_ffff).
 template <typename Enum>
-struct format_provider<
+struct format_provider<Enum, std::enable_if_t<dwarf::EnumTraits<Enum>::value>> {
-    Enum, typename std::enable_if<dwarf::EnumTraits<Enum>::value>::type> {
   static void format(const Enum &E, raw_ostream &OS, StringRef Style) {
     StringRef Str = dwarf::EnumTraits<Enum>::StringFn(E);
     if (Str.empty()) {

include/llvm/CodeGen/LiveInterval.h

@@ -625,11 +625,12 @@ namespace llvm {
         // if the Seg is lower find first segment that is above Idx using binary
         // search
         if (Seg->end <= *Idx) {
-          Seg = std::upper_bound(++Seg, EndSeg, *Idx,
+          Seg = std::upper_bound(
-            [=](typename std::remove_reference<decltype(*Idx)>::type V,
+              ++Seg, EndSeg, *Idx,
-                const typename std::remove_reference<decltype(*Seg)>::type &S) {
+              [=](std::remove_reference_t<decltype(*Idx)> V,
-              return V < S.end;
+                  const std::remove_reference_t<decltype(*Seg)> &S) {
-            });
+                return V < S.end;
+              });
           if (Seg == EndSeg)
             break;
         }

include/llvm/CodeGen/MachineInstrBundleIterator.h

@@ -152,8 +152,8 @@ public:
   template <class OtherTy>
   MachineInstrBundleIterator(
       const MachineInstrBundleIterator<OtherTy, IsReverse> &I,
-      typename std::enable_if<std::is_convertible<OtherTy *, Ty *>::value,
+      std::enable_if_t<std::is_convertible<OtherTy *, Ty *>::value, void *> =
-                              void *>::type = nullptr)
+          nullptr)
       : MII(I.getInstrIterator()) {}
 
   MachineInstrBundleIterator() : MII(nullptr) {}

include/llvm/DebugInfo/CodeView/CodeViewRecordIO.h

@@ -114,7 +114,7 @@ public:
     if (!isStreaming() && sizeof(Value) > maxFieldLength())
       return make_error<CodeViewError>(cv_error_code::insufficient_buffer);
 
-    using U = typename std::underlying_type<T>::type;
+    using U = std::underlying_type_t<T>;
     U X;
 
     if (isWriting() || isStreaming())

include/llvm/ExecutionEngine/JITSymbol.h

@@ -58,10 +58,9 @@ template <typename T> T jitTargetAddressToPointer(JITTargetAddress Addr) {
 /// Casts the given address to a callable function pointer. This operation
 /// will perform pointer signing for platforms that require it (e.g. arm64e).
 template <typename T> T jitTargetAddressToFunction(JITTargetAddress Addr) {
-  static_assert(
+  static_assert(std::is_pointer<T>::value &&
-      std::is_pointer<T>::value &&
+                    std::is_function<std::remove_pointer_t<T>>::value,
-          std::is_function<typename std::remove_pointer<T>::type>::value,
+                "T must be a function pointer type");
-      "T must be a function pointer type");
   return jitTargetAddressToPointer<T>(Addr);
 }
 

include/llvm/ExecutionEngine/Orc/Core.h

@@ -202,10 +202,10 @@ public:
   /// If Body returns true then the element just passed in is removed from the
   /// set. If Body returns false then the element is retained.
   template <typename BodyFn>
-  auto forEachWithRemoval(BodyFn &&Body) -> typename std::enable_if<
+  auto forEachWithRemoval(BodyFn &&Body) -> std::enable_if_t<
       std::is_same<decltype(Body(std::declval<const SymbolStringPtr &>(),
                                  std::declval<SymbolLookupFlags>())),
-                   bool>::value>::type {
+                   bool>::value> {
     UnderlyingVector::size_type I = 0;
     while (I != Symbols.size()) {
       const auto &Name = Symbols[I].first;
@@ -224,11 +224,11 @@ public:
   /// returns true then the element just passed in is removed from the set. If
   /// Body returns false then the element is retained.
   template <typename BodyFn>
-  auto forEachWithRemoval(BodyFn &&Body) -> typename std::enable_if<
+  auto forEachWithRemoval(BodyFn &&Body) -> std::enable_if_t<
       std::is_same<decltype(Body(std::declval<const SymbolStringPtr &>(),
                                  std::declval<SymbolLookupFlags>())),
                    Expected<bool>>::value,
-      Error>::type {
+      Error> {
     UnderlyingVector::size_type I = 0;
     while (I != Symbols.size()) {
       const auto &Name = Symbols[I].first;

include/llvm/ExecutionEngine/Orc/Legacy.h

@@ -73,17 +73,13 @@ private:
 ///        function objects.
 template <typename GetResponsibilitySetFn, typename LookupFn>
 std::unique_ptr<LambdaSymbolResolver<
-    typename std::remove_cv<
+    std::remove_cv_t<std::remove_reference_t<GetResponsibilitySetFn>>,
-        typename std::remove_reference<GetResponsibilitySetFn>::type>::type,
+    std::remove_cv_t<std::remove_reference_t<LookupFn>>>>
-    typename std::remove_cv<
-        typename std::remove_reference<LookupFn>::type>::type>>
 createSymbolResolver(GetResponsibilitySetFn &&GetResponsibilitySet,
                      LookupFn &&Lookup) {
   using LambdaSymbolResolverImpl = LambdaSymbolResolver<
-      typename std::remove_cv<
+      std::remove_cv_t<std::remove_reference_t<GetResponsibilitySetFn>>,
-          typename std::remove_reference<GetResponsibilitySetFn>::type>::type,
+      std::remove_cv_t<std::remove_reference_t<LookupFn>>>;
-      typename std::remove_cv<
-          typename std::remove_reference<LookupFn>::type>::type>;
   return std::make_unique<LambdaSymbolResolverImpl>(
       std::forward<GetResponsibilitySetFn>(GetResponsibilitySet),
       std::forward<LookupFn>(Lookup));

include/llvm/ExecutionEngine/Orc/OrcRemoteTargetRPCAPI.h

@@ -108,8 +108,7 @@ public:
 template <typename ChannelT>
 class SerializationTraits<
     ChannelT, remote::DirectBufferWriter, remote::DirectBufferWriter,
-    typename std::enable_if<
+    std::enable_if_t<std::is_base_of<RawByteChannel, ChannelT>::value>> {
-        std::is_base_of<RawByteChannel, ChannelT>::value>::type> {
 public:
   static Error serialize(ChannelT &C, const remote::DirectBufferWriter &DBW) {
     if (auto EC = serializeSeq(C, DBW.getDst()))

include/llvm/ExecutionEngine/Orc/OrcRemoteTargetServer.h

@@ -60,7 +60,7 @@ public:
         SymbolLookup(std::move(SymbolLookup)),
         EHFramesRegister(std::move(EHFramesRegister)),
         EHFramesDeregister(std::move(EHFramesDeregister)) {
-    using ThisT = typename std::remove_reference<decltype(*this)>::type;
+    using ThisT = std::remove_reference_t<decltype(*this)>;
     addHandler<exec::CallIntVoid>(*this, &ThisT::handleCallIntVoid);
     addHandler<exec::CallMain>(*this, &ThisT::handleCallMain);
     addHandler<exec::CallVoidVoid>(*this, &ThisT::handleCallVoidVoid);

include/llvm/ExecutionEngine/Orc/RPC/RPCSerialization.h

@@ -230,9 +230,9 @@ public:
 ///
 ///   template <DerivedChannelT>
 ///   class SerializationTraits<DerivedChannelT, bool,
-///         typename std::enable_if<
+///         std::enable_if_t<
 ///           std::is_base_of<VirtChannel, DerivedChannel>::value
-///         >::type> {
+///         >> {
 ///   public:
 ///     static const char* getName() { ... };
 ///   }
@@ -274,9 +274,8 @@ public:
 
   template <typename CArgT>
   static Error serialize(ChannelT &C, CArgT &&CArg) {
-    return SerializationTraits<ChannelT, ArgT,
+    return SerializationTraits<ChannelT, ArgT, std::decay_t<CArgT>>::serialize(
-                               typename std::decay<CArgT>::type>::
+        C, std::forward<CArgT>(CArg));
-             serialize(C, std::forward<CArgT>(CArg));
   }
 
   template <typename CArgT>
@@ -293,8 +292,8 @@ public:
   static Error serialize(ChannelT &C, CArgT &&CArg,
                          CArgTs &&... CArgs) {
     if (auto Err =
-        SerializationTraits<ChannelT, ArgT, typename std::decay<CArgT>::type>::
+            SerializationTraits<ChannelT, ArgT, std::decay_t<CArgT>>::serialize(
-          serialize(C, std::forward<CArgT>(CArg)))
+                C, std::forward<CArgT>(CArg)))
       return Err;
     if (auto Err = SequenceTraits<ChannelT>::emitSeparator(C))
       return Err;
@@ -316,8 +315,8 @@ public:
 
 template <typename ChannelT, typename... ArgTs>
 Error serializeSeq(ChannelT &C, ArgTs &&... Args) {
-  return SequenceSerialization<ChannelT, typename std::decay<ArgTs>::type...>::
+  return SequenceSerialization<ChannelT, std::decay_t<ArgTs>...>::serialize(
-           serialize(C, std::forward<ArgTs>(Args)...);
+      C, std::forward<ArgTs>(Args)...);
 }
 
 template <typename ChannelT, typename... ArgTs>

include/llvm/ExecutionEngine/Orc/RPC/RPCUtils.h

@@ -184,8 +184,7 @@ template <typename T, typename = void> class RPCFunctionIdAllocator;
 /// This specialization of RPCFunctionIdAllocator provides a default
 /// implementation for integral types.
 template <typename T>
-class RPCFunctionIdAllocator<
+class RPCFunctionIdAllocator<T, std::enable_if_t<std::is_integral<T>::value>> {
-    T, typename std::enable_if<std::is_integral<T>::value>::type> {
 public:
   static T getInvalidId() { return T(0); }
   static T getResponseId() { return T(1); }
@@ -205,8 +204,7 @@ template <typename T> class FunctionArgsTuple;
 template <typename RetT, typename... ArgTs>
 class FunctionArgsTuple<RetT(ArgTs...)> {
 public:
-  using Type = std::tuple<typename std::decay<
+  using Type = std::tuple<std::decay_t<std::remove_reference_t<ArgTs>>...>;
-      typename std::remove_reference<ArgTs>::type>::type...>;
 };
 
 // ResultTraits provides typedefs and utilities specific to the return type
@@ -483,9 +481,9 @@ public:
 };
 
 template <typename ResponseHandlerT, typename... ArgTs>
-class AsyncHandlerTraits<Error(ResponseHandlerT, ArgTs...)> :
+class AsyncHandlerTraits<Error(ResponseHandlerT, ArgTs...)>
-    public AsyncHandlerTraits<Error(typename std::decay<ResponseHandlerT>::type,
+    : public AsyncHandlerTraits<Error(std::decay_t<ResponseHandlerT>,
-                                    ArgTs...)> {};
+                                      ArgTs...)> {};
 
 // This template class provides utilities related to RPC function handlers.
 // The base case applies to non-function types (the template class is
@@ -524,18 +522,17 @@ public:
 
   // Call the given handler with the given arguments.
   template <typename HandlerT>
-  static typename std::enable_if<
+  static std::enable_if_t<
-      std::is_void<typename HandlerTraits<HandlerT>::ReturnType>::value,
+      std::is_void<typename HandlerTraits<HandlerT>::ReturnType>::value, Error>
-      Error>::type
   run(HandlerT &Handler, ArgTs &&... Args) {
     Handler(std::move(Args)...);
     return Error::success();
   }
 
   template <typename HandlerT, typename... TArgTs>
-  static typename std::enable_if<
+  static std::enable_if_t<
       !std::is_void<typename HandlerTraits<HandlerT>::ReturnType>::value,
-      typename HandlerTraits<HandlerT>::ReturnType>::type
+      typename HandlerTraits<HandlerT>::ReturnType>
   run(HandlerT &Handler, TArgTs... Args) {
     return Handler(std::move(Args)...);
   }
@@ -894,12 +891,12 @@ private:
   using S = SerializationTraits<ChannelT, WireT, ConcreteT>;
 
   template <typename T>
-  static std::true_type
+  static std::true_type check(
-  check(typename std::enable_if<
+      std::enable_if_t<std::is_same<decltype(T::serialize(
-        std::is_same<decltype(T::serialize(std::declval<ChannelT &>(),
+                                        std::declval<ChannelT &>(),
-                                           std::declval<const ConcreteT &>())),
+                                        std::declval<const ConcreteT &>())),
-                     Error>::value,
+                                    Error>::value,
-        void *>::type);
+                       void *>);
 
   template <typename> static std::false_type check(...);
 
@@ -914,11 +911,11 @@ private:
 
   template <typename T>
   static std::true_type
-  check(typename std::enable_if<
+      check(std::enable_if_t<
-        std::is_same<decltype(T::deserialize(std::declval<ChannelT &>(),
+            std::is_same<decltype(T::deserialize(std::declval<ChannelT &>(),
-                                             std::declval<ConcreteT &>())),
+                                                 std::declval<ConcreteT &>())),
-                     Error>::value,
+                         Error>::value,
-        void *>::type);
+            void *>);
 
   template <typename> static std::false_type check(...);
 

include/llvm/ExecutionEngine/Orc/RPC/RawByteChannel.h

@@ -87,13 +87,13 @@ private:
 template <typename ChannelT, typename T>
 class SerializationTraits<
     ChannelT, T, T,
-    typename std::enable_if<
+    std::enable_if_t<
         std::is_base_of<RawByteChannel, ChannelT>::value &&
         (std::is_same<T, uint8_t>::value || std::is_same<T, int8_t>::value ||
          std::is_same<T, uint16_t>::value || std::is_same<T, int16_t>::value ||
          std::is_same<T, uint32_t>::value || std::is_same<T, int32_t>::value ||
          std::is_same<T, uint64_t>::value || std::is_same<T, int64_t>::value ||
-         std::is_same<T, char>::value)>::type> {
+         std::is_same<T, char>::value)>> {
 public:
   static Error serialize(ChannelT &C, T V) {
     support::endian::byte_swap<T, support::big>(V);
@@ -109,9 +109,9 @@ public:
 };
 
 template <typename ChannelT>
-class SerializationTraits<ChannelT, bool, bool,
+class SerializationTraits<
-                          typename std::enable_if<std::is_base_of<
+    ChannelT, bool, bool,
-                              RawByteChannel, ChannelT>::value>::type> {
+    std::enable_if_t<std::is_base_of<RawByteChannel, ChannelT>::value>> {
 public:
   static Error serialize(ChannelT &C, bool V) {
     uint8_t Tmp = V ? 1 : 0;
@@ -131,9 +131,9 @@ public:
 };
 
 template <typename ChannelT>
-class SerializationTraits<ChannelT, std::string, StringRef,
+class SerializationTraits<
-                          typename std::enable_if<std::is_base_of<
+    ChannelT, std::string, StringRef,
-                              RawByteChannel, ChannelT>::value>::type> {
+    std::enable_if_t<std::is_base_of<RawByteChannel, ChannelT>::value>> {
 public:
   /// RPC channel serialization for std::strings.
   static Error serialize(RawByteChannel &C, StringRef S) {
@@ -144,11 +144,11 @@ public:
 };
 
 template <typename ChannelT, typename T>
-class SerializationTraits<ChannelT, std::string, T,
+class SerializationTraits<
-                          typename std::enable_if<
+    ChannelT, std::string, T,
-                            std::is_base_of<RawByteChannel, ChannelT>::value &&
+    std::enable_if_t<std::is_base_of<RawByteChannel, ChannelT>::value &&
-                            (std::is_same<T, const char*>::value ||
+                     (std::is_same<T, const char *>::value ||
-                             std::is_same<T, char*>::value)>::type> {
+                      std::is_same<T, char *>::value)>> {
 public:
   static Error serialize(RawByteChannel &C, const char *S) {
     return SerializationTraits<ChannelT, std::string, StringRef>::serialize(C,
@@ -157,9 +157,9 @@ public:
 };
 
 template <typename ChannelT>
-class SerializationTraits<ChannelT, std::string, std::string,
+class SerializationTraits<
-                          typename std::enable_if<std::is_base_of<
+    ChannelT, std::string, std::string,
-                              RawByteChannel, ChannelT>::value>::type> {
+    std::enable_if_t<std::is_base_of<RawByteChannel, ChannelT>::value>> {
 public:
   /// RPC channel serialization for std::strings.
   static Error serialize(RawByteChannel &C, const std::string &S) {

include/llvm/FuzzMutate/Random.h

@@ -32,7 +32,7 @@ template <typename T, typename GenT> T uniform(GenT &Gen) {
 /// elements, which may each be weighted to be more likely choices.
 template <typename T, typename GenT> class ReservoirSampler {
   GenT &RandGen;
-  typename std::remove_const<T>::type Selection = {};
+  std::remove_const_t<T> Selection = {};
   uint64_t TotalWeight = 0;
 
 public:
@@ -70,8 +70,8 @@ public:
 };
 
 template <typename GenT, typename RangeT,
-          typename ElT = typename std::remove_reference<
+          typename ElT = std::remove_reference_t<
-              decltype(*std::begin(std::declval<RangeT>()))>::type>
+              decltype(*std::begin(std::declval<RangeT>()))>>
 ReservoirSampler<ElT, GenT> makeSampler(GenT &RandGen, RangeT &&Items) {
   ReservoirSampler<ElT, GenT> RS(RandGen);
   RS.sample(Items);

include/llvm/IR/Constants.h

@@ -460,8 +460,7 @@ public:
   static Constant *get(StructType *T, ArrayRef<Constant*> V);
 
   template <typename... Csts>
-  static typename std::enable_if<are_base_of<Constant, Csts...>::value,
+  static std::enable_if_t<are_base_of<Constant, Csts...>::value, Constant *>
-                                 Constant *>::type
   get(StructType *T, Csts *... Vs) {
     SmallVector<Constant *, 8> Values({Vs...});
     return get(T, Values);

include/llvm/IR/DerivedTypes.h

@@ -267,8 +267,7 @@ public:
                             StringRef Name, bool isPacked = false);
   static StructType *create(LLVMContext &Context, ArrayRef<Type *> Elements);
   template <class... Tys>
-  static typename std::enable_if<are_base_of<Type, Tys...>::value,
+  static std::enable_if_t<are_base_of<Type, Tys...>::value, StructType *>
-                                 StructType *>::type
   create(StringRef Name, Type *elt1, Tys *... elts) {
     assert(elt1 && "Cannot create a struct type with no elements with this");
     SmallVector<llvm::Type *, 8> StructFields({elt1, elts...});
@@ -286,8 +285,7 @@ public:
   /// specifying the elements as arguments. Note that this method always returns
   /// a non-packed struct, and requires at least one element type.
   template <class... Tys>
-  static typename std::enable_if<are_base_of<Type, Tys...>::value,
+  static std::enable_if_t<are_base_of<Type, Tys...>::value, StructType *>
-                                 StructType *>::type
   get(Type *elt1, Tys *... elts) {
     assert(elt1 && "Cannot create a struct type with no elements with this");
     LLVMContext &Ctx = elt1->getContext();
@@ -324,7 +322,7 @@ public:
   void setBody(ArrayRef<Type*> Elements, bool isPacked = false);
 
   template <typename... Tys>
-  typename std::enable_if<are_base_of<Type, Tys...>::value, void>::type
+  std::enable_if_t<are_base_of<Type, Tys...>::value, void>
   setBody(Type *elt1, Tys *... elts) {
     assert(elt1 && "Cannot create a struct type with no elements with this");
     SmallVector<llvm::Type *, 8> StructFields({elt1, elts...});

include/llvm/IR/DiagnosticInfo.h

@@ -531,9 +531,10 @@ protected:
 template <class RemarkT>
 RemarkT &
 operator<<(RemarkT &R,
-           typename std::enable_if<
+           std::enable_if_t<
                std::is_base_of<DiagnosticInfoOptimizationBase, RemarkT>::value,
-               StringRef>::type S) {
+               StringRef>
+               S) {
   R.insert(S);
   return R;
 }
@@ -543,9 +544,10 @@ operator<<(RemarkT &R,
 template <class RemarkT>
 RemarkT &
 operator<<(RemarkT &&R,
-           typename std::enable_if<
+           std::enable_if_t<
                std::is_base_of<DiagnosticInfoOptimizationBase, RemarkT>::value,
-               StringRef>::type S) {
+               StringRef>
+               S) {
   R.insert(S);
   return R;
 }
@@ -553,9 +555,10 @@ operator<<(RemarkT &&R,
 template <class RemarkT>
 RemarkT &
 operator<<(RemarkT &R,
-           typename std::enable_if<
+           std::enable_if_t<
                std::is_base_of<DiagnosticInfoOptimizationBase, RemarkT>::value,
-               DiagnosticInfoOptimizationBase::Argument>::type A) {
+               DiagnosticInfoOptimizationBase::Argument>
+               A) {
   R.insert(A);
   return R;
 }
@@ -563,9 +566,10 @@ operator<<(RemarkT &R,
 template <class RemarkT>
 RemarkT &
 operator<<(RemarkT &&R,
-           typename std::enable_if<
+           std::enable_if_t<
                std::is_base_of<DiagnosticInfoOptimizationBase, RemarkT>::value,
-               DiagnosticInfoOptimizationBase::Argument>::type A) {
+               DiagnosticInfoOptimizationBase::Argument>
+               A) {
   R.insert(A);
   return R;
 }
@@ -573,9 +577,10 @@ operator<<(RemarkT &&R,
 template <class RemarkT>
 RemarkT &
 operator<<(RemarkT &R,
-           typename std::enable_if<
+           std::enable_if_t<
                std::is_base_of<DiagnosticInfoOptimizationBase, RemarkT>::value,
-               DiagnosticInfoOptimizationBase::setIsVerbose>::type V) {
+               DiagnosticInfoOptimizationBase::setIsVerbose>
+               V) {
   R.insert(V);
   return R;
 }
@@ -583,9 +588,10 @@ operator<<(RemarkT &R,
 template <class RemarkT>
 RemarkT &
 operator<<(RemarkT &&R,
-           typename std::enable_if<
+           std::enable_if_t<
                std::is_base_of<DiagnosticInfoOptimizationBase, RemarkT>::value,
-               DiagnosticInfoOptimizationBase::setIsVerbose>::type V) {
+               DiagnosticInfoOptimizationBase::setIsVerbose>
+               V) {
   R.insert(V);
   return R;
 }
@@ -593,9 +599,10 @@ operator<<(RemarkT &&R,
 template <class RemarkT>
 RemarkT &
 operator<<(RemarkT &R,
-           typename std::enable_if<
+           std::enable_if_t<
                std::is_base_of<DiagnosticInfoOptimizationBase, RemarkT>::value,
-               DiagnosticInfoOptimizationBase::setExtraArgs>::type EA) {
+               DiagnosticInfoOptimizationBase::setExtraArgs>
+               EA) {
   R.insert(EA);
   return R;
 }

include/llvm/IR/Metadata.h

@@ -527,7 +527,7 @@ template <class V, class M> struct IsValidReference {
 /// As an analogue to \a isa(), check whether \c MD has an \a Value inside of
 /// type \c X.
 template <class X, class Y>
-inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, bool>::type
+inline std::enable_if_t<detail::IsValidPointer<X, Y>::value, bool>
 hasa(Y &&MD) {
   assert(MD && "Null pointer sent into hasa");
   if (auto *V = dyn_cast<ConstantAsMetadata>(MD))
@@ -535,9 +535,8 @@ hasa(Y &&MD) {
   return false;
 }
 template <class X, class Y>
-inline
+inline std::enable_if_t<detail::IsValidReference<X, Y &>::value, bool>
-    typename std::enable_if<detail::IsValidReference<X, Y &>::value, bool>::type
+hasa(Y &MD) {
-    hasa(Y &MD) {
   return hasa(&MD);
 }
 
@@ -545,14 +544,13 @@ inline
 ///
 /// As an analogue to \a cast(), extract the \a Value subclass \c X from \c MD.
 template <class X, class Y>
-inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type
+inline std::enable_if_t<detail::IsValidPointer<X, Y>::value, X *>
 extract(Y &&MD) {
   return cast<X>(cast<ConstantAsMetadata>(MD)->getValue());
 }
 template <class X, class Y>
-inline
+inline std::enable_if_t<detail::IsValidReference<X, Y &>::value, X *>
-    typename std::enable_if<detail::IsValidReference<X, Y &>::value, X *>::type
+extract(Y &MD) {
-    extract(Y &MD) {
   return extract(&MD);
 }
 
@@ -561,7 +559,7 @@ inline
 /// As an analogue to \a cast_or_null(), extract the \a Value subclass \c X
 /// from \c MD, allowing \c MD to be null.
 template <class X, class Y>
-inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type
+inline std::enable_if_t<detail::IsValidPointer<X, Y>::value, X *>
 extract_or_null(Y &&MD) {
   if (auto *V = cast_or_null<ConstantAsMetadata>(MD))
     return cast<X>(V->getValue());
@@ -574,7 +572,7 @@ extract_or_null(Y &&MD) {
 /// from \c MD, return null if \c MD doesn't contain a \a Value or if the \a
 /// Value it does contain is of the wrong subclass.
 template <class X, class Y>
-inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type
+inline std::enable_if_t<detail::IsValidPointer<X, Y>::value, X *>
 dyn_extract(Y &&MD) {
   if (auto *V = dyn_cast<ConstantAsMetadata>(MD))
     return dyn_cast<X>(V->getValue());
@@ -587,7 +585,7 @@ dyn_extract(Y &&MD) {
 /// from \c MD, return null if \c MD doesn't contain a \a Value or if the \a
 /// Value it does contain is of the wrong subclass, allowing \c MD to be null.
 template <class X, class Y>
-inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type
+inline std::enable_if_t<detail::IsValidPointer<X, Y>::value, X *>
 dyn_extract_or_null(Y &&MD) {
   if (auto *V = dyn_cast_or_null<ConstantAsMetadata>(MD))
     return dyn_cast<X>(V->getValue());
@@ -976,7 +974,7 @@ public:
   /// Try to create a uniqued version of \c N -- in place, if possible -- and
   /// return it.  If \c N cannot be uniqued, return a distinct node instead.
   template <class T>
-  static typename std::enable_if<std::is_base_of<MDNode, T>::value, T *>::type
+  static std::enable_if_t<std::is_base_of<MDNode, T>::value, T *>
   replaceWithPermanent(std::unique_ptr<T, TempMDNodeDeleter> N) {
     return cast<T>(N.release()->replaceWithPermanentImpl());
   }
@@ -988,7 +986,7 @@ public:
   ///
   /// \pre N does not self-reference.
   template <class T>
-  static typename std::enable_if<std::is_base_of<MDNode, T>::value, T *>::type
+  static std::enable_if_t<std::is_base_of<MDNode, T>::value, T *>
   replaceWithUniqued(std::unique_ptr<T, TempMDNodeDeleter> N) {
     return cast<T>(N.release()->replaceWithUniquedImpl());
   }
@@ -998,7 +996,7 @@ public:
   /// Create a distinct version of \c N -- in place, if possible -- and return
   /// it.  Takes ownership of the temporary node.
   template <class T>
-  static typename std::enable_if<std::is_base_of<MDNode, T>::value, T *>::type
+  static std::enable_if_t<std::is_base_of<MDNode, T>::value, T *>
   replaceWithDistinct(std::unique_ptr<T, TempMDNodeDeleter> N) {
     return cast<T>(N.release()->replaceWithDistinctImpl());
   }
@@ -1237,15 +1235,13 @@ public:
   template <class U>
   MDTupleTypedArrayWrapper(
       const MDTupleTypedArrayWrapper<U> &Other,
-      typename std::enable_if<std::is_convertible<U *, T *>::value>::type * =
+      std::enable_if_t<std::is_convertible<U *, T *>::value> * = nullptr)
-          nullptr)
       : N(Other.get()) {}
 
   template <class U>
   explicit MDTupleTypedArrayWrapper(
       const MDTupleTypedArrayWrapper<U> &Other,
-      typename std::enable_if<!std::is_convertible<U *, T *>::value>::type * =
+      std::enable_if_t<!std::is_convertible<U *, T *>::value> * = nullptr)
-          nullptr)
       : N(Other.get()) {}
 
   explicit operator bool() const { return get(); }

include/llvm/IR/ValueMap.h

@@ -243,7 +243,7 @@ class ValueMapCallbackVH final : public CallbackVH {
   friend struct DenseMapInfo<ValueMapCallbackVH>;
 
   using ValueMapT = ValueMap<KeyT, ValueT, Config>;
-  using KeySansPointerT = typename std::remove_pointer<KeyT>::type;
+  using KeySansPointerT = std::remove_pointer_t<KeyT>;
 
   ValueMapT *Map;
 

include/llvm/Object/ELFTypes.h

@@ -53,7 +53,7 @@ public:
   static const endianness TargetEndianness = E;
   static const bool Is64Bits = Is64;
 
-  using uint = typename std::conditional<Is64, uint64_t, uint32_t>::type;
+  using uint = std::conditional_t<Is64, uint64_t, uint32_t>;
   using Ehdr = Elf_Ehdr_Impl<ELFType<E, Is64>>;
   using Shdr = Elf_Shdr_Impl<ELFType<E, Is64>>;
   using Sym = Elf_Sym_Impl<ELFType<E, Is64>>;
@@ -346,10 +346,8 @@ template <class ELFT>
 struct Elf_Dyn_Impl : Elf_Dyn_Base<ELFT> {
   using Elf_Dyn_Base<ELFT>::d_tag;
   using Elf_Dyn_Base<ELFT>::d_un;
-  using intX_t = typename std::conditional<ELFT::Is64Bits,
+  using intX_t = std::conditional_t<ELFT::Is64Bits, int64_t, int32_t>;
-                                           int64_t, int32_t>::type;
+  using uintX_t = std::conditional_t<ELFT::Is64Bits, uint64_t, uint32_t>;
-  using uintX_t = typename std::conditional<ELFT::Is64Bits,
-                                            uint64_t, uint32_t>::type;
   intX_t getTag() const { return d_tag; }
   uintX_t getVal() const { return d_un.d_val; }
   uintX_t getPtr() const { return d_un.d_ptr; }

include/llvm/Support/AllocatorBase.h

@@ -70,8 +70,7 @@ public:
 
   /// Deallocate space for a sequence of objects without constructing them.
   template <typename T>
-  typename std::enable_if<
+  std::enable_if_t<!std::is_same<std::remove_cv_t<T>, void>::value, void>
-      !std::is_same<typename std::remove_cv<T>::type, void>::value, void>::type
   Deallocate(T *Ptr, size_t Num = 1) {
     Deallocate(static_cast<const void *>(Ptr), Num * sizeof(T));
   }

include/llvm/Support/BinaryStreamReader.h

@@ -90,7 +90,7 @@ public:
   template <typename T> Error readEnum(T &Dest) {
     static_assert(std::is_enum<T>::value,
                   "Cannot call readEnum with non-enum value!");
-    typename std::underlying_type<T>::type N;
+    std::underlying_type_t<T> N;
     if (auto EC = readInteger(N))
       return EC;
     Dest = static_cast<T>(N);

include/llvm/Support/BinaryStreamWriter.h

@@ -75,7 +75,7 @@ public:
     static_assert(std::is_enum<T>::value,
                   "Cannot call writeEnum with non-Enum type");
 
-    using U = typename std::underlying_type<T>::type;
+    using U = std::underlying_type_t<T>;
     return writeInteger<U>(static_cast<U>(Num));
   }
 

include/llvm/Support/Casting.h

@@ -61,8 +61,7 @@ struct isa_impl {
 
 /// Always allow upcasts, and perform no dynamic check for them.
 template <typename To, typename From>
-struct isa_impl<
+struct isa_impl<To, From, std::enable_if_t<std::is_base_of<To, From>::value>> {
-    To, From, typename std::enable_if<std::is_base_of<To, From>::value>::type> {
   static inline bool doit(const From &) { return true; }
 };
 
@@ -184,7 +183,7 @@ template <class To, class From>
 struct cast_retty_impl<To, std::unique_ptr<From>> {
 private:
   using PointerType = typename cast_retty_impl<To, From *>::ret_type;
-  using ResultType = typename std::remove_pointer<PointerType>::type;
+  using ResultType = std::remove_pointer_t<PointerType>;
 
 public:
   using ret_type = std::unique_ptr<ResultType>;
@@ -244,8 +243,8 @@ template <class X> struct is_simple_type {
 //  cast<Instruction>(myVal)->getParent()
 //
 template <class X, class Y>
-inline typename std::enable_if<!is_simple_type<Y>::value,
+inline std::enable_if_t<!is_simple_type<Y>::value,
-                               typename cast_retty<X, const Y>::ret_type>::type
+                        typename cast_retty<X, const Y>::ret_type>
 cast(const Y &Val) {
   assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!");
   return cast_convert_val<
@@ -280,10 +279,9 @@ cast(std::unique_ptr<Y> &&Val) {
 // accepted.
 //
 template <class X, class Y>
-LLVM_NODISCARD inline
+LLVM_NODISCARD inline std::enable_if_t<
-    typename std::enable_if<!is_simple_type<Y>::value,
+    !is_simple_type<Y>::value, typename cast_retty<X, const Y>::ret_type>
-                            typename cast_retty<X, const Y>::ret_type>::type
+cast_or_null(const Y &Val) {
-    cast_or_null(const Y &Val) {
   if (!Val)
     return nullptr;
   assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!");
@@ -291,10 +289,9 @@ LLVM_NODISCARD inline
 }
 
 template <class X, class Y>
-LLVM_NODISCARD inline
+LLVM_NODISCARD inline std::enable_if_t<!is_simple_type<Y>::value,
-    typename std::enable_if<!is_simple_type<Y>::value,
+                                       typename cast_retty<X, Y>::ret_type>
-                            typename cast_retty<X, Y>::ret_type>::type
+cast_or_null(Y &Val) {
-    cast_or_null(Y &Val) {
   if (!Val)
     return nullptr;
   assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!");
@@ -326,10 +323,9 @@ cast_or_null(std::unique_ptr<Y> &&Val) {
 //
 
 template <class X, class Y>
-LLVM_NODISCARD inline
+LLVM_NODISCARD inline std::enable_if_t<
-    typename std::enable_if<!is_simple_type<Y>::value,
+    !is_simple_type<Y>::value, typename cast_retty<X, const Y>::ret_type>
-                            typename cast_retty<X, const Y>::ret_type>::type
+dyn_cast(const Y &Val) {
-    dyn_cast(const Y &Val) {
   return isa<X>(Val) ? cast<X>(Val) : nullptr;
 }
 
@@ -347,18 +343,16 @@ LLVM_NODISCARD inline typename cast_retty<X, Y *>::ret_type dyn_cast(Y *Val) {
 // value is accepted.
 //
 template <class X, class Y>
-LLVM_NODISCARD inline
+LLVM_NODISCARD inline std::enable_if_t<
-    typename std::enable_if<!is_simple_type<Y>::value,
+    !is_simple_type<Y>::value, typename cast_retty<X, const Y>::ret_type>
-                            typename cast_retty<X, const Y>::ret_type>::type
+dyn_cast_or_null(const Y &Val) {
-    dyn_cast_or_null(const Y &Val) {
   return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr;
 }
 
 template <class X, class Y>
-LLVM_NODISCARD inline
+LLVM_NODISCARD inline std::enable_if_t<!is_simple_type<Y>::value,
-    typename std::enable_if<!is_simple_type<Y>::value,
+                                       typename cast_retty<X, Y>::ret_type>
-                            typename cast_retty<X, Y>::ret_type>::type
+dyn_cast_or_null(Y &Val) {
-    dyn_cast_or_null(Y &Val) {
   return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr;
 }
 

include/llvm/Support/CheckedArithmetic.h

@@ -25,8 +25,8 @@ namespace {
 /// \p RHS.
 /// \return Empty optional if the operation overflows, or result otherwise.
 template <typename T, typename F>
-typename std::enable_if<std::is_integral<T>::value && sizeof(T) * 8 <= 64,
+std::enable_if_t<std::is_integral<T>::value && sizeof(T) * 8 <= 64,
-                        llvm::Optional<T>>::type
+                 llvm::Optional<T>>
 checkedOp(T LHS, T RHS, F Op, bool Signed = true) {
   llvm::APInt ALHS(/*BitSize=*/sizeof(T) * 8, LHS, Signed);
   llvm::APInt ARHS(/*BitSize=*/sizeof(T) * 8, RHS, Signed);
@@ -44,7 +44,7 @@ namespace llvm {
 /// \return Optional of sum if no signed overflow occurred,
 /// \c None otherwise.
 template <typename T>
-typename std::enable_if<std::is_signed<T>::value, llvm::Optional<T>>::type
+std::enable_if_t<std::is_signed<T>::value, llvm::Optional<T>>
 checkedAdd(T LHS, T RHS) {
   return checkedOp(LHS, RHS, &llvm::APInt::sadd_ov);
 }
@@ -53,7 +53,7 @@ checkedAdd(T LHS, T RHS) {
 /// \return Optional of sum if no signed overflow occurred,
 /// \c None otherwise.
 template <typename T>
-typename std::enable_if<std::is_signed<T>::value, llvm::Optional<T>>::type
+std::enable_if_t<std::is_signed<T>::value, llvm::Optional<T>>
 checkedSub(T LHS, T RHS) {
   return checkedOp(LHS, RHS, &llvm::APInt::ssub_ov);
 }
@@ -62,7 +62,7 @@ checkedSub(T LHS, T RHS) {
 /// \return Optional of product if no signed overflow occurred,
 /// \c None otherwise.
 template <typename T>
-typename std::enable_if<std::is_signed<T>::value, llvm::Optional<T>>::type
+std::enable_if_t<std::is_signed<T>::value, llvm::Optional<T>>
 checkedMul(T LHS, T RHS) {
   return checkedOp(LHS, RHS, &llvm::APInt::smul_ov);
 }
@@ -71,7 +71,7 @@ checkedMul(T LHS, T RHS) {
 /// \return Optional of result if no signed overflow occurred,
 /// \c None otherwise.
 template <typename T>
-typename std::enable_if<std::is_signed<T>::value, llvm::Optional<T>>::type
+std::enable_if_t<std::is_signed<T>::value, llvm::Optional<T>>
 checkedMulAdd(T A, T B, T C) {
   if (auto Product = checkedMul(A, B))
     return checkedAdd(*Product, C);
@@ -82,7 +82,7 @@ checkedMulAdd(T A, T B, T C) {
 /// \return Optional of sum if no unsigned overflow occurred,
 /// \c None otherwise.
 template <typename T>
-typename std::enable_if<std::is_unsigned<T>::value, llvm::Optional<T>>::type
+std::enable_if_t<std::is_unsigned<T>::value, llvm::Optional<T>>
 checkedAddUnsigned(T LHS, T RHS) {
   return checkedOp(LHS, RHS, &llvm::APInt::uadd_ov, /*Signed=*/false);
 }
@@ -91,7 +91,7 @@ checkedAddUnsigned(T LHS, T RHS) {
 /// \return Optional of product if no unsigned overflow occurred,
 /// \c None otherwise.
 template <typename T>
-typename std::enable_if<std::is_unsigned<T>::value, llvm::Optional<T>>::type
+std::enable_if_t<std::is_unsigned<T>::value, llvm::Optional<T>>
 checkedMulUnsigned(T LHS, T RHS) {
   return checkedOp(LHS, RHS, &llvm::APInt::umul_ov, /*Signed=*/false);
 }
@@ -100,7 +100,7 @@ checkedMulUnsigned(T LHS, T RHS) {
 /// \return Optional of result if no unsigned overflow occurred,
 /// \c None otherwise.
 template <typename T>
-typename std::enable_if<std::is_unsigned<T>::value, llvm::Optional<T>>::type
+std::enable_if_t<std::is_unsigned<T>::value, llvm::Optional<T>>
 checkedMulAddUnsigned(T A, T B, T C) {
   if (auto Product = checkedMulUnsigned(A, B))
     return checkedAddUnsigned(*Product, C);

include/llvm/Support/Chrono.h

@@ -112,8 +112,8 @@ template <typename Rep, typename Period>
 struct format_provider<std::chrono::duration<Rep, Period>> {
 private:
   typedef std::chrono::duration<Rep, Period> Dur;
-  typedef typename std::conditional<
+  typedef std::conditional_t<std::chrono::treat_as_floating_point<Rep>::value,
-      std::chrono::treat_as_floating_point<Rep>::value, double, intmax_t>::type
+                             double, intmax_t>
       InternalRep;
 
   template <typename AsPeriod> static InternalRep getAs(const Dur &D) {

include/llvm/Support/CommandLine.h

@@ -488,14 +488,13 @@ struct callback_traits : public callback_traits<decltype(&F::operator())> {};
 template <typename R, typename C, typename... Args>
 struct callback_traits<R (C::*)(Args...) const> {
   using result_type = R;
-  using arg_type = typename std::tuple_element<0, std::tuple<Args...>>::type;
+  using arg_type = std::tuple_element_t<0, std::tuple<Args...>>;
   static_assert(sizeof...(Args) == 1, "callback function must have one and only one parameter");
   static_assert(std::is_same<result_type, void>::value,
                 "callback return type must be void");
-  static_assert(
+  static_assert(std::is_lvalue_reference<arg_type>::value &&
-      std::is_lvalue_reference<arg_type>::value &&
+                    std::is_const<std::remove_reference_t<arg_type>>::value,
-          std::is_const<typename std::remove_reference<arg_type>::type>::value,
+                "callback arg_type must be a const lvalue reference");
-      "callback arg_type must be a const lvalue reference");
 };
 } // namespace detail
 
@@ -1453,16 +1452,16 @@ class opt : public Option,
     }
   }
 
-  template <class T, class = typename std::enable_if<
+  template <class T,
-            std::is_assignable<T&, T>::value>::type>
+            class = std::enable_if_t<std::is_assignable<T &, T>::value>>
   void setDefaultImpl() {
     const OptionValue<DataType> &V = this->getDefault();
     if (V.hasValue())
       this->setValue(V.getValue());
   }
 
-  template <class T, class = typename std::enable_if<
+  template <class T,
-            !std::is_assignable<T&, T>::value>::type>
+            class = std::enable_if_t<!std::is_assignable<T &, T>::value>>
   void setDefaultImpl(...) {}
 
   void setDefault() override { setDefaultImpl<DataType>(); }

include/llvm/Support/Endian.h

@@ -111,7 +111,7 @@ inline void write(void *memory, value_type value) {
 }
 
 template <typename value_type>
-using make_unsigned_t = typename std::make_unsigned<value_type>::type;
+using make_unsigned_t = std::make_unsigned_t<value_type>;
 
 /// Read a value of a particular endianness from memory, for a location
 /// that starts at the given bit offset within the first byte.

include/llvm/Support/Error.h

@@ -436,19 +436,19 @@ template <class T> class LLVM_NODISCARD Expected {
 
   static const bool isRef = std::is_reference<T>::value;
 
-  using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
+  using wrap = std::reference_wrapper<std::remove_reference_t<T>>;
 
   using error_type = std::unique_ptr<ErrorInfoBase>;
 
 public:
-  using storage_type = typename std::conditional<isRef, wrap, T>::type;
+  using storage_type = std::conditional_t<isRef, wrap, T>;
   using value_type = T;
 
 private:
-  using reference = typename std::remove_reference<T>::type &;
+  using reference = std::remove_reference_t<T> &;
-  using const_reference = const typename std::remove_reference<T>::type &;
+  using const_reference = const std::remove_reference_t<T> &;
-  using pointer = typename std::remove_reference<T>::type *;
+  using pointer = std::remove_reference_t<T> *;
-  using const_pointer = const typename std::remove_reference<T>::type *;
+  using const_pointer = const std::remove_reference_t<T> *;
 
 public:
   /// Create an Expected<T> error value from the given Error.
@@ -472,12 +472,12 @@ public:
   /// must be convertible to T.
   template <typename OtherT>
   Expected(OtherT &&Val,
-           typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
+           std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr)
-               * = nullptr)
       : HasError(false)
 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
         // Expected is unchecked upon construction in Debug builds.
-        , Unchecked(true)
+        ,
+        Unchecked(true)
 #endif
   {
     new (getStorage()) storage_type(std::forward<OtherT>(Val));
@@ -489,9 +489,9 @@ public:
   /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
   /// must be convertible to T.
   template <class OtherT>
-  Expected(Expected<OtherT> &&Other,
+  Expected(
-           typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
+      Expected<OtherT> &&Other,
-               * = nullptr) {
+      std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) {
     moveConstruct(std::move(Other));
   }
 
@@ -500,8 +500,7 @@ public:
   template <class OtherT>
   explicit Expected(
       Expected<OtherT> &&Other,
-      typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
+      std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr) {
-          nullptr) {
     moveConstruct(std::move(Other));
   }
 

include/llvm/Support/ErrorOr.h

@@ -58,23 +58,23 @@ class ErrorOr {
 
   static const bool isRef = std::is_reference<T>::value;
 
-  using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
+  using wrap = std::reference_wrapper<std::remove_reference_t<T>>;
 
 public:
-  using storage_type = typename std::conditional<isRef, wrap, T>::type;
+  using storage_type = std::conditional_t<isRef, wrap, T>;
 
 private:
-  using reference = typename std::remove_reference<T>::type &;
+  using reference = std::remove_reference_t<T> &;
-  using const_reference = const typename std::remove_reference<T>::type &;
+  using const_reference = const std::remove_reference_t<T> &;
-  using pointer = typename std::remove_reference<T>::type *;
+  using pointer = std::remove_reference_t<T> *;
-  using const_pointer = const typename std::remove_reference<T>::type *;
+  using const_pointer = const std::remove_reference_t<T> *;
 
 public:
   template <class E>
   ErrorOr(E ErrorCode,
-          typename std::enable_if<std::is_error_code_enum<E>::value ||
+          std::enable_if_t<std::is_error_code_enum<E>::value ||
-                                      std::is_error_condition_enum<E>::value,
+                               std::is_error_condition_enum<E>::value,
-                                  void *>::type = nullptr)
+                           void *> = nullptr)
       : HasError(true) {
     new (getErrorStorage()) std::error_code(make_error_code(ErrorCode));
   }
@@ -85,8 +85,7 @@ public:
 
   template <class OtherT>
   ErrorOr(OtherT &&Val,
-          typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
+          std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr)
-              * = nullptr)
       : HasError(false) {
     new (getStorage()) storage_type(std::forward<OtherT>(Val));
   }
@@ -96,18 +95,16 @@ public:
   }
 
   template <class OtherT>
-  ErrorOr(
+  ErrorOr(const ErrorOr<OtherT> &Other,
-      const ErrorOr<OtherT> &Other,
+          std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) {
-      typename std::enable_if<std::is_convertible<OtherT, T>::value>::type * =
-          nullptr) {
     copyConstruct(Other);
   }
 
   template <class OtherT>
   explicit ErrorOr(
       const ErrorOr<OtherT> &Other,
-      typename std::enable_if<
+      std::enable_if_t<!std::is_convertible<OtherT, const T &>::value> * =
-          !std::is_convertible<OtherT, const T &>::value>::type * = nullptr) {
+          nullptr) {
     copyConstruct(Other);
   }
 
@@ -116,10 +113,8 @@ public:
   }
 
   template <class OtherT>
-  ErrorOr(
+  ErrorOr(ErrorOr<OtherT> &&Other,
-      ErrorOr<OtherT> &&Other,
+          std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) {
-      typename std::enable_if<std::is_convertible<OtherT, T>::value>::type * =
-          nullptr) {
     moveConstruct(std::move(Other));
   }
 
@@ -128,8 +123,7 @@ public:
   template <class OtherT>
   explicit ErrorOr(
       ErrorOr<OtherT> &&Other,
-      typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
+      std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr) {
-          nullptr) {
     moveConstruct(std::move(Other));
   }
 
@@ -266,9 +260,9 @@ private:
 };
 
 template <class T, class E>
-typename std::enable_if<std::is_error_code_enum<E>::value ||
+std::enable_if_t<std::is_error_code_enum<E>::value ||
-                            std::is_error_condition_enum<E>::value,
+                     std::is_error_condition_enum<E>::value,
-                        bool>::type
+                 bool>
 operator==(const ErrorOr<T> &Err, E Code) {
   return Err.getError() == Code;
 }

include/llvm/Support/FormatProviders.h

@@ -124,7 +124,7 @@ protected:
 
 template <typename T>
 struct format_provider<
-    T, typename std::enable_if<detail::use_integral_formatter<T>::value>::type>
+    T, std::enable_if_t<detail::use_integral_formatter<T>::value>>
     : public detail::HelperFunctions {
 private:
 public:
@@ -173,7 +173,7 @@ public:
 /// cases indicates the minimum number of nibbles to print.
 template <typename T>
 struct format_provider<
-    T, typename std::enable_if<detail::use_pointer_formatter<T>::value>::type>
+    T, std::enable_if_t<detail::use_pointer_formatter<T>::value>>
     : public detail::HelperFunctions {
 private:
 public:
@@ -198,7 +198,7 @@ public:
 
 template <typename T>
 struct format_provider<
-    T, typename std::enable_if<detail::use_string_formatter<T>::value>::type> {
+    T, std::enable_if_t<detail::use_string_formatter<T>::value>> {
   static void format(const T &V, llvm::raw_ostream &Stream, StringRef Style) {
     size_t N = StringRef::npos;
     if (!Style.empty() && Style.getAsInteger(10, N)) {
@@ -230,8 +230,8 @@ template <> struct format_provider<Twine> {
 /// character.  Otherwise, it is treated as an integer options string.
 ///
 template <typename T>
-struct format_provider<
+struct format_provider<T,
-    T, typename std::enable_if<detail::use_char_formatter<T>::value>::type> {
+                       std::enable_if_t<detail::use_char_formatter<T>::value>> {
   static void format(const char &V, llvm::raw_ostream &Stream,
                      StringRef Style) {
     if (Style.empty())
@@ -296,8 +296,8 @@ template <> struct format_provider<bool> {
 /// else.
 
 template <typename T>
-struct format_provider<
+struct format_provider<T,
-    T, typename std::enable_if<detail::use_double_formatter<T>::value>::type>
+                       std::enable_if_t<detail::use_double_formatter<T>::value>>
     : public detail::HelperFunctions {
   static void format(const T &V, llvm::raw_ostream &Stream, StringRef Style) {
     FloatStyle S;

include/llvm/Support/FormatVariadicDetails.h

@@ -36,7 +36,7 @@ public:
   explicit provider_format_adapter(T &&Item) : Item(std::forward<T>(Item)) {}
 
   void format(llvm::raw_ostream &S, StringRef Options) override {
-    format_provider<typename std::decay<T>::type>::format(Item, S, Options);
+    format_provider<std::decay_t<T>>::format(Item, S, Options);
   }
 };
 
@@ -59,7 +59,7 @@ template <typename T> class missing_format_adapter;
 //
 template <class T> class has_FormatProvider {
 public:
-  using Decayed = typename std::decay<T>::type;
+  using Decayed = std::decay_t<T>;
   typedef void (*Signature_format)(const Decayed &, llvm::raw_ostream &,
                                    StringRef);
 
@@ -75,14 +75,14 @@ public:
 // Test if raw_ostream& << T -> raw_ostream& is findable via ADL.
 template <class T> class has_StreamOperator {
 public:
-  using ConstRefT = const typename std::decay<T>::type &;
+  using ConstRefT = const std::decay_t<T> &;
 
   template <typename U>
-  static char test(typename std::enable_if<
+  static char test(
-                   std::is_same<decltype(std::declval<llvm::raw_ostream &>()
+      std::enable_if_t<std::is_same<decltype(std::declval<llvm::raw_ostream &>()
-                                         << std::declval<U>()),
+                                             << std::declval<U>()),
-                                llvm::raw_ostream &>::value,
+                                    llvm::raw_ostream &>::value,
-                   int *>::type);
+                       int *>);
 
   template <typename U> static double test(...);
 
@@ -95,8 +95,8 @@ template <typename T>
 struct uses_format_member
     : public std::integral_constant<
           bool,
-          std::is_base_of<format_adapter,
+          std::is_base_of<format_adapter, std::remove_reference_t<T>>::value> {
-                          typename std::remove_reference<T>::type>::value> {};
+};
 
 // Simple template that decides whether a type T should use the format_provider
 // based format() invocation.  The member function takes priority, so this test
@@ -127,34 +127,32 @@ struct uses_missing_provider
 };
 
 template <typename T>
-typename std::enable_if<uses_format_member<T>::value, T>::type
+std::enable_if_t<uses_format_member<T>::value, T>
 build_format_adapter(T &&Item) {
   return std::forward<T>(Item);
 }
 
 template <typename T>
-typename std::enable_if<uses_format_provider<T>::value,
+std::enable_if_t<uses_format_provider<T>::value, provider_format_adapter<T>>
-                        provider_format_adapter<T>>::type
 build_format_adapter(T &&Item) {
   return provider_format_adapter<T>(std::forward<T>(Item));
 }
 
 template <typename T>
-typename std::enable_if<uses_stream_operator<T>::value,
+std::enable_if_t<uses_stream_operator<T>::value,
-                        stream_operator_format_adapter<T>>::type
+                 stream_operator_format_adapter<T>>
 build_format_adapter(T &&Item) {
   // If the caller passed an Error by value, then stream_operator_format_adapter
   // would be responsible for consuming it.
   // Make the caller opt into this by calling fmt_consume().
   static_assert(
-      !std::is_same<llvm::Error, typename std::remove_cv<T>::type>::value,
+      !std::is_same<llvm::Error, std::remove_cv_t<T>>::value,
       "llvm::Error-by-value must be wrapped in fmt_consume() for formatv");
   return stream_operator_format_adapter<T>(std::forward<T>(Item));
 }
 
 template <typename T>
-typename std::enable_if<uses_missing_provider<T>::value,
+std::enable_if_t<uses_missing_provider<T>::value, missing_format_adapter<T>>
-                        missing_format_adapter<T>>::type
 build_format_adapter(T &&Item) {
   return missing_format_adapter<T>();
 }

include/llvm/Support/GenericDomTree.h

@@ -225,7 +225,7 @@ class DominatorTreeBase {
   using ParentPtr = decltype(std::declval<NodeT *>()->getParent());
   static_assert(std::is_pointer<ParentPtr>::value,
                 "Currently NodeT's parent must be a pointer type");
-  using ParentType = typename std::remove_pointer<ParentPtr>::type;
+  using ParentType = std::remove_pointer_t<ParentPtr>;
   static constexpr bool IsPostDominator = IsPostDom;
 
   using UpdateType = cfg::Update<NodePtr>;

include/llvm/Support/GenericIteratedDominanceFrontier.h

@@ -57,7 +57,7 @@ template <class NodeTy, bool IsPostDom> struct ChildrenGetterTy {
 template <class NodeTy, bool IsPostDom> class IDFCalculatorBase {
 public:
   using OrderedNodeTy =
-      typename std::conditional<IsPostDom, Inverse<NodeTy *>, NodeTy *>::type;
+      std::conditional_t<IsPostDom, Inverse<NodeTy *>, NodeTy *>;
   using ChildrenGetterTy =
       IDFCalculatorDetail::ChildrenGetterTy<NodeTy, IsPostDom>;
 

include/llvm/Support/JSON.h

@@ -329,25 +329,21 @@ public:
   Value(std::nullptr_t) : Type(T_Null) {}
   // Boolean (disallow implicit conversions).
   // (The last template parameter is a dummy to keep templates distinct.)
-  template <
+  template <typename T,
-      typename T,
+            typename = std::enable_if_t<std::is_same<T, bool>::value>,
-      typename = typename std::enable_if<std::is_same<T, bool>::value>::type,
+            bool = false>
-      bool = false>
   Value(T B) : Type(T_Boolean) {
     create<bool>(B);
   }
   // Integers (except boolean). Must be non-narrowing convertible to int64_t.
-  template <
+  template <typename T, typename = std::enable_if_t<std::is_integral<T>::value>,
-      typename T,
+            typename = std::enable_if_t<!std::is_same<T, bool>::value>>
-      typename = typename std::enable_if<std::is_integral<T>::value>::type,
-      typename = typename std::enable_if<!std::is_same<T, bool>::value>::type>
   Value(T I) : Type(T_Integer) {
     create<int64_t>(int64_t{I});
   }
   // Floating point. Must be non-narrowing convertible to double.
   template <typename T,
-            typename =
+            typename = std::enable_if_t<std::is_floating_point<T>::value>,
-                typename std::enable_if<std::is_floating_point<T>::value>::type,
             double * = nullptr>
   Value(T D) : Type(T_Double) {
     create<double>(double{D});

include/llvm/Support/MSVCErrorWorkarounds.h

@@ -59,22 +59,19 @@ public:
   template <typename OtherT>
   MSVCPExpected(
       OtherT &&Val,
-      typename std::enable_if<std::is_convertible<OtherT, T>::value>::type * =
+      std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr)
-          nullptr)
       : Expected<T>(std::move(Val)) {}
 
   template <class OtherT>
   MSVCPExpected(
       Expected<OtherT> &&Other,
-      typename std::enable_if<std::is_convertible<OtherT, T>::value>::type * =
+      std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr)
-          nullptr)
       : Expected<T>(std::move(Other)) {}
 
   template <class OtherT>
   explicit MSVCPExpected(
       Expected<OtherT> &&Other,
-      typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
+      std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr)
-          nullptr)
       : Expected<T>(std::move(Other)) {}
 };
 

include/llvm/Support/MathExtras.h

@@ -364,14 +364,12 @@ constexpr inline bool isShiftedInt(int64_t x) {
 /// to keep MSVC from (incorrectly) warning on isUInt<64> that we're shifting
 /// left too many places.
 template <unsigned N>
-constexpr inline typename std::enable_if<(N < 64), bool>::type
+constexpr inline std::enable_if_t<(N < 64), bool> isUInt(uint64_t X) {
-isUInt(uint64_t X) {
   static_assert(N > 0, "isUInt<0> doesn't make sense");
   return X < (UINT64_C(1) << (N));
 }
 template <unsigned N>
-constexpr inline typename std::enable_if<N >= 64, bool>::type
+constexpr inline std::enable_if_t<N >= 64, bool> isUInt(uint64_t X) {
-isUInt(uint64_t X) {
   return true;
 }
 
@@ -780,8 +778,7 @@ inline int64_t SignExtend64(uint64_t X, unsigned B) {
 /// Subtract two unsigned integers, X and Y, of type T and return the absolute
 /// value of the result.
 template <typename T>
-typename std::enable_if<std::is_unsigned<T>::value, T>::type
+std::enable_if_t<std::is_unsigned<T>::value, T> AbsoluteDifference(T X, T Y) {
-AbsoluteDifference(T X, T Y) {
   return std::max(X, Y) - std::min(X, Y);
 }
 
@@ -789,7 +786,7 @@ AbsoluteDifference(T X, T Y) {
 /// maximum representable value of T on overflow.  ResultOverflowed indicates if
 /// the result is larger than the maximum representable value of type T.
 template <typename T>
-typename std::enable_if<std::is_unsigned<T>::value, T>::type
+std::enable_if_t<std::is_unsigned<T>::value, T>
 SaturatingAdd(T X, T Y, bool *ResultOverflowed = nullptr) {
   bool Dummy;
   bool &Overflowed = ResultOverflowed ? *ResultOverflowed : Dummy;
@@ -806,7 +803,7 @@ SaturatingAdd(T X, T Y, bool *ResultOverflowed = nullptr) {
 /// maximum representable value of T on overflow.  ResultOverflowed indicates if
 /// the result is larger than the maximum representable value of type T.
 template <typename T>
-typename std::enable_if<std::is_unsigned<T>::value, T>::type
+std::enable_if_t<std::is_unsigned<T>::value, T>
 SaturatingMultiply(T X, T Y, bool *ResultOverflowed = nullptr) {
   bool Dummy;
   bool &Overflowed = ResultOverflowed ? *ResultOverflowed : Dummy;
@@ -852,7 +849,7 @@ SaturatingMultiply(T X, T Y, bool *ResultOverflowed = nullptr) {
 /// overflow. ResultOverflowed indicates if the result is larger than the
 /// maximum representable value of type T.
 template <typename T>
-typename std::enable_if<std::is_unsigned<T>::value, T>::type
+std::enable_if_t<std::is_unsigned<T>::value, T>
 SaturatingMultiplyAdd(T X, T Y, T A, bool *ResultOverflowed = nullptr) {
   bool Dummy;
   bool &Overflowed = ResultOverflowed ? *ResultOverflowed : Dummy;
@@ -871,13 +868,12 @@ extern const float huge_valf;
 /// Add two signed integers, computing the two's complement truncated result,
 /// returning true if overflow occured.
 template <typename T>
-typename std::enable_if<std::is_signed<T>::value, T>::type
+std::enable_if_t<std::is_signed<T>::value, T> AddOverflow(T X, T Y, T &Result) {
-AddOverflow(T X, T Y, T &Result) {
 #if __has_builtin(__builtin_add_overflow)
   return __builtin_add_overflow(X, Y, &Result);
 #else
   // Perform the unsigned addition.
-  using U = typename std::make_unsigned<T>::type;
+  using U = std::make_unsigned_t<T>;
   const U UX = static_cast<U>(X);
   const U UY = static_cast<U>(Y);
   const U UResult = UX + UY;
@@ -898,13 +894,12 @@ AddOverflow(T X, T Y, T &Result) {
 /// Subtract two signed integers, computing the two's complement truncated
 /// result, returning true if an overflow ocurred.
 template <typename T>
-typename std::enable_if<std::is_signed<T>::value, T>::type
+std::enable_if_t<std::is_signed<T>::value, T> SubOverflow(T X, T Y, T &Result) {
-SubOverflow(T X, T Y, T &Result) {
 #if __has_builtin(__builtin_sub_overflow)
   return __builtin_sub_overflow(X, Y, &Result);
 #else
   // Perform the unsigned addition.
-  using U = typename std::make_unsigned<T>::type;
+  using U = std::make_unsigned_t<T>;
   const U UX = static_cast<U>(X);
   const U UY = static_cast<U>(Y);
   const U UResult = UX - UY;
@@ -922,14 +917,12 @@ SubOverflow(T X, T Y, T &Result) {
 #endif
 }
 
-
 /// Multiply two signed integers, computing the two's complement truncated
 /// result, returning true if an overflow ocurred.
 template <typename T>
-typename std::enable_if<std::is_signed<T>::value, T>::type
+std::enable_if_t<std::is_signed<T>::value, T> MulOverflow(T X, T Y, T &Result) {
-MulOverflow(T X, T Y, T &Result) {
   // Perform the unsigned multiplication on absolute values.
-  using U = typename std::make_unsigned<T>::type;
+  using U = std::make_unsigned_t<T>;
   const U UX = X < 0 ? (0 - static_cast<U>(X)) : static_cast<U>(X);
   const U UY = Y < 0 ? (0 - static_cast<U>(Y)) : static_cast<U>(Y);
   const U UResult = UX * UY;

include/llvm/Support/SwapByteOrder.h

@@ -143,10 +143,9 @@ inline double getSwappedBytes(double C) {
 }
 
 template <typename T>
-inline typename std::enable_if<std::is_enum<T>::value, T>::type
+inline std::enable_if_t<std::is_enum<T>::value, T> getSwappedBytes(T C) {
-getSwappedBytes(T C) {
   return static_cast<T>(
-      getSwappedBytes(static_cast<typename std::underlying_type<T>::type>(C)));
+      getSwappedBytes(static_cast<std::underlying_type_t<T>>(C)));
 }
 
 template<typename T>

include/llvm/Support/TaskQueue.h

@@ -38,7 +38,7 @@ class TaskQueue {
   // type-specialized domain (before type erasure) and then erase this into a
   // std::function.
   template <typename Callable> struct Task {
-    using ResultTy = typename std::result_of<Callable()>::type;
+    using ResultTy = std::result_of_t<Callable()>;
     explicit Task(Callable C, TaskQueue &Parent)
         : C(std::move(C)), P(std::make_shared<std::promise<ResultTy>>()),
           Parent(&Parent) {}
@@ -78,13 +78,13 @@ public:
   /// used to wait for the task (and all previous tasks that have not yet
   /// completed) to finish.
   template <typename Callable>
-  std::future<typename std::result_of<Callable()>::type> async(Callable &&C) {
+  std::future<std::result_of_t<Callable()>> async(Callable &&C) {
 #if !LLVM_ENABLE_THREADS
     static_assert(false,
                   "TaskQueue requires building with LLVM_ENABLE_THREADS!");
 #endif
     Task<Callable> T{std::move(C), *this};
-    using ResultTy = typename std::result_of<Callable()>::type;
+    using ResultTy = std::result_of_t<Callable()>;
     std::future<ResultTy> F = T.P->get_future();
     {
       std::lock_guard<std::mutex> Lock(QueueLock);

include/llvm/Support/TrailingObjects.h

@@ -326,8 +326,8 @@ public:
   /// used in the class; they are supplied here redundantly only so
   /// that it's clear what the counts are counting in callers.
   template <typename... Tys>
-  static constexpr typename std::enable_if<
+  static constexpr std::enable_if_t<
-      std::is_same<Foo<TrailingTys...>, Foo<Tys...>>::value, size_t>::type
+      std::is_same<Foo<TrailingTys...>, Foo<Tys...>>::value, size_t>
   additionalSizeToAlloc(typename trailing_objects_internal::ExtractSecondType<
                         TrailingTys, size_t>::type... Counts) {
     return ParentType::additionalSizeToAllocImpl(0, Counts...);
@@ -338,8 +338,8 @@ public:
   /// additionalSizeToAlloc, except it *does* include the size of the base
   /// object.
   template <typename... Tys>
-  static constexpr typename std::enable_if<
+  static constexpr std::enable_if_t<
-      std::is_same<Foo<TrailingTys...>, Foo<Tys...>>::value, size_t>::type
+      std::is_same<Foo<TrailingTys...>, Foo<Tys...>>::value, size_t>
   totalSizeToAlloc(typename trailing_objects_internal::ExtractSecondType<
                    TrailingTys, size_t>::type... Counts) {
     return sizeof(BaseTy) + ParentType::additionalSizeToAllocImpl(0, Counts...);

include/llvm/Support/YAMLTraits.h

@@ -868,7 +868,7 @@ public:
   }
 
   template <typename T, typename Context>
-  typename std::enable_if<has_SequenceTraits<T>::value, void>::type
+  std::enable_if_t<has_SequenceTraits<T>::value, void>
   mapOptionalWithContext(const char *Key, T &Val, Context &Ctx) {
     // omit key/value instead of outputting empty sequence
     if (this->canElideEmptySequence() && !(Val.begin() != Val.end()))
@@ -883,7 +883,7 @@ public:
   }
 
   template <typename T, typename Context>
-  typename std::enable_if<!has_SequenceTraits<T>::value, void>::type
+  std::enable_if_t<!has_SequenceTraits<T>::value, void>
   mapOptionalWithContext(const char *Key, T &Val, Context &Ctx) {
     this->processKey(Key, Val, false, Ctx);
   }
@@ -965,7 +965,7 @@ template <typename T> void doMapping(IO &io, T &Val, EmptyContext &Ctx) {
 } // end namespace detail
 
 template <typename T>
-typename std::enable_if<has_ScalarEnumerationTraits<T>::value, void>::type
+std::enable_if_t<has_ScalarEnumerationTraits<T>::value, void>
 yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
   io.beginEnumScalar();
   ScalarEnumerationTraits<T>::enumeration(io, Val);
@@ -973,7 +973,7 @@ yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
 }
 
 template <typename T>
-typename std::enable_if<has_ScalarBitSetTraits<T>::value, void>::type
+std::enable_if_t<has_ScalarBitSetTraits<T>::value, void>
 yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
   bool DoClear;
   if ( io.beginBitSetScalar(DoClear) ) {
@@ -985,8 +985,8 @@ yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
 }
 
 template <typename T>
-typename std::enable_if<has_ScalarTraits<T>::value, void>::type
+std::enable_if_t<has_ScalarTraits<T>::value, void> yamlize(IO &io, T &Val, bool,
-yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
+                                                           EmptyContext &Ctx) {
   if ( io.outputting() ) {
     std::string Storage;
     raw_string_ostream Buffer(Storage);
@@ -1005,7 +1005,7 @@ yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
 }
 
 template <typename T>
-typename std::enable_if<has_BlockScalarTraits<T>::value, void>::type
+std::enable_if_t<has_BlockScalarTraits<T>::value, void>
 yamlize(IO &YamlIO, T &Val, bool, EmptyContext &Ctx) {
   if (YamlIO.outputting()) {
     std::string Storage;
@@ -1024,7 +1024,7 @@ yamlize(IO &YamlIO, T &Val, bool, EmptyContext &Ctx) {
 }
 
 template <typename T>
-typename std::enable_if<has_TaggedScalarTraits<T>::value, void>::type
+std::enable_if_t<has_TaggedScalarTraits<T>::value, void>
 yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
   if (io.outputting()) {
     std::string ScalarStorage, TagStorage;
@@ -1049,7 +1049,7 @@ yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
 }
 
 template <typename T, typename Context>
-typename std::enable_if<validatedMappingTraits<T, Context>::value, void>::type
+std::enable_if_t<validatedMappingTraits<T, Context>::value, void>
 yamlize(IO &io, T &Val, bool, Context &Ctx) {
   if (has_FlowTraits<MappingTraits<T>>::value)
     io.beginFlowMapping();
@@ -1075,7 +1075,7 @@ yamlize(IO &io, T &Val, bool, Context &Ctx) {
 }
 
 template <typename T, typename Context>
-typename std::enable_if<unvalidatedMappingTraits<T, Context>::value, void>::type
+std::enable_if_t<unvalidatedMappingTraits<T, Context>::value, void>
 yamlize(IO &io, T &Val, bool, Context &Ctx) {
   if (has_FlowTraits<MappingTraits<T>>::value) {
     io.beginFlowMapping();
@@ -1089,7 +1089,7 @@ yamlize(IO &io, T &Val, bool, Context &Ctx) {
 }
 
 template <typename T>
-typename std::enable_if<has_CustomMappingTraits<T>::value, void>::type
+std::enable_if_t<has_CustomMappingTraits<T>::value, void>
 yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
   if ( io.outputting() ) {
     io.beginMapping();
@@ -1104,7 +1104,7 @@ yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
 }
 
 template <typename T>
-typename std::enable_if<has_PolymorphicTraits<T>::value, void>::type
+std::enable_if_t<has_PolymorphicTraits<T>::value, void>
 yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
   switch (io.outputting() ? PolymorphicTraits<T>::getKind(Val)
                           : io.getNodeKind()) {
@@ -1118,13 +1118,13 @@ yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
 }
 
 template <typename T>
-typename std::enable_if<missingTraits<T, EmptyContext>::value, void>::type
+std::enable_if_t<missingTraits<T, EmptyContext>::value, void>
 yamlize(IO &io, T &Val, bool, EmptyContext &Ctx) {
   char missing_yaml_trait_for_type[sizeof(MissingTrait<T>)];
 }
 
 template <typename T, typename Context>
-typename std::enable_if<has_SequenceTraits<T>::value, void>::type
+std::enable_if_t<has_SequenceTraits<T>::value, void>
 yamlize(IO &io, T &Seq, bool, Context &Ctx) {
   if ( has_FlowTraits< SequenceTraits<T>>::value ) {
     unsigned incnt = io.beginFlowSequence();
@@ -1247,10 +1247,9 @@ struct ScalarTraits<double> {
 // type.  This way endian aware types are supported whenever the traits are
 // defined for the underlying type.
 template <typename value_type, support::endianness endian, size_t alignment>
-struct ScalarTraits<
+struct ScalarTraits<support::detail::packed_endian_specific_integral<
-    support::detail::packed_endian_specific_integral<value_type, endian,
+                        value_type, endian, alignment>,
-                                                     alignment>,
+                    std::enable_if_t<has_ScalarTraits<value_type>::value>> {
-    typename std::enable_if<has_ScalarTraits<value_type>::value>::type> {
   using endian_type =
       support::detail::packed_endian_specific_integral<value_type, endian,
                                                        alignment>;
@@ -1275,8 +1274,7 @@ template <typename value_type, support::endianness endian, size_t alignment>
 struct ScalarEnumerationTraits<
     support::detail::packed_endian_specific_integral<value_type, endian,
                                                      alignment>,
-    typename std::enable_if<
+    std::enable_if_t<has_ScalarEnumerationTraits<value_type>::value>> {
-        has_ScalarEnumerationTraits<value_type>::value>::type> {
   using endian_type =
       support::detail::packed_endian_specific_integral<value_type, endian,
                                                        alignment>;
@@ -1292,7 +1290,7 @@ template <typename value_type, support::endianness endian, size_t alignment>
 struct ScalarBitSetTraits<
     support::detail::packed_endian_specific_integral<value_type, endian,
                                                      alignment>,
-    typename std::enable_if<has_ScalarBitSetTraits<value_type>::value>::type> {
+    std::enable_if_t<has_ScalarBitSetTraits<value_type>::value>> {
   using endian_type =
       support::detail::packed_endian_specific_integral<value_type, endian,
                                                        alignment>;
@@ -1688,8 +1686,7 @@ struct ScalarTraits<Hex64> {
 
 // Define non-member operator>> so that Input can stream in a document list.
 template <typename T>
-inline
+inline std::enable_if_t<has_DocumentListTraits<T>::value, Input &>
-typename std::enable_if<has_DocumentListTraits<T>::value, Input &>::type
 operator>>(Input &yin, T &docList) {
   int i = 0;
   EmptyContext Ctx;
@@ -1705,8 +1702,7 @@ operator>>(Input &yin, T &docList) {
 
 // Define non-member operator>> so that Input can stream in a map as a document.
 template <typename T>
-inline typename std::enable_if<has_MappingTraits<T, EmptyContext>::value,
+inline std::enable_if_t<has_MappingTraits<T, EmptyContext>::value, Input &>
-                               Input &>::type
 operator>>(Input &yin, T &docMap) {
   EmptyContext Ctx;
   yin.setCurrentDocument();
@@ -1717,8 +1713,7 @@ operator>>(Input &yin, T &docMap) {
 // Define non-member operator>> so that Input can stream in a sequence as
 // a document.
 template <typename T>
-inline
+inline std::enable_if_t<has_SequenceTraits<T>::value, Input &>
-typename std::enable_if<has_SequenceTraits<T>::value, Input &>::type
 operator>>(Input &yin, T &docSeq) {
   EmptyContext Ctx;
   if (yin.setCurrentDocument())
@@ -1728,8 +1723,7 @@ operator>>(Input &yin, T &docSeq) {
 
 // Define non-member operator>> so that Input can stream in a block scalar.
 template <typename T>
-inline
+inline std::enable_if_t<has_BlockScalarTraits<T>::value, Input &>
-typename std::enable_if<has_BlockScalarTraits<T>::value, Input &>::type
 operator>>(Input &In, T &Val) {
   EmptyContext Ctx;
   if (In.setCurrentDocument())
@@ -1739,8 +1733,7 @@ operator>>(Input &In, T &Val) {
 
 // Define non-member operator>> so that Input can stream in a string map.
 template <typename T>
-inline
+inline std::enable_if_t<has_CustomMappingTraits<T>::value, Input &>
-typename std::enable_if<has_CustomMappingTraits<T>::value, Input &>::type
 operator>>(Input &In, T &Val) {
   EmptyContext Ctx;
   if (In.setCurrentDocument())
@@ -1750,7 +1743,7 @@ operator>>(Input &In, T &Val) {
 
 // Define non-member operator>> so that Input can stream in a polymorphic type.
 template <typename T>
-inline typename std::enable_if<has_PolymorphicTraits<T>::value, Input &>::type
+inline std::enable_if_t<has_PolymorphicTraits<T>::value, Input &>
 operator>>(Input &In, T &Val) {
   EmptyContext Ctx;
   if (In.setCurrentDocument())
@@ -1760,8 +1753,7 @@ operator>>(Input &In, T &Val) {
 
 // Provide better error message about types missing a trait specialization
 template <typename T>
-inline typename std::enable_if<missingTraits<T, EmptyContext>::value,
+inline std::enable_if_t<missingTraits<T, EmptyContext>::value, Input &>
-                               Input &>::type
 operator>>(Input &yin, T &docSeq) {
   char missing_yaml_trait_for_type[sizeof(MissingTrait<T>)];
   return yin;
@@ -1769,8 +1761,7 @@ operator>>(Input &yin, T &docSeq) {
 
 // Define non-member operator<< so that Output can stream out document list.
 template <typename T>
-inline
+inline std::enable_if_t<has_DocumentListTraits<T>::value, Output &>
-typename std::enable_if<has_DocumentListTraits<T>::value, Output &>::type
 operator<<(Output &yout, T &docList) {
   EmptyContext Ctx;
   yout.beginDocuments();
@@ -1788,8 +1779,7 @@ operator<<(Output &yout, T &docList) {
 
 // Define non-member operator<< so that Output can stream out a map.
 template <typename T>
-inline typename std::enable_if<has_MappingTraits<T, EmptyContext>::value,
+inline std::enable_if_t<has_MappingTraits<T, EmptyContext>::value, Output &>
-                               Output &>::type
 operator<<(Output &yout, T &map) {
   EmptyContext Ctx;
   yout.beginDocuments();
@@ -1803,8 +1793,7 @@ operator<<(Output &yout, T &map) {
 
 // Define non-member operator<< so that Output can stream out a sequence.
 template <typename T>
-inline
+inline std::enable_if_t<has_SequenceTraits<T>::value, Output &>
-typename std::enable_if<has_SequenceTraits<T>::value, Output &>::type
 operator<<(Output &yout, T &seq) {
   EmptyContext Ctx;
   yout.beginDocuments();
@@ -1818,8 +1807,7 @@ operator<<(Output &yout, T &seq) {
 
 // Define non-member operator<< so that Output can stream out a block scalar.
 template <typename T>
-inline
+inline std::enable_if_t<has_BlockScalarTraits<T>::value, Output &>
-typename std::enable_if<has_BlockScalarTraits<T>::value, Output &>::type
 operator<<(Output &Out, T &Val) {
   EmptyContext Ctx;
   Out.beginDocuments();
@@ -1833,8 +1821,7 @@ operator<<(Output &Out, T &Val) {
 
 // Define non-member operator<< so that Output can stream out a string map.
 template <typename T>
-inline
+inline std::enable_if_t<has_CustomMappingTraits<T>::value, Output &>
-typename std::enable_if<has_CustomMappingTraits<T>::value, Output &>::type
 operator<<(Output &Out, T &Val) {
   EmptyContext Ctx;
   Out.beginDocuments();
@@ -1849,7 +1836,7 @@ operator<<(Output &Out, T &Val) {
 // Define non-member operator<< so that Output can stream out a polymorphic
 // type.
 template <typename T>
-inline typename std::enable_if<has_PolymorphicTraits<T>::value, Output &>::type
+inline std::enable_if_t<has_PolymorphicTraits<T>::value, Output &>
 operator<<(Output &Out, T &Val) {
   EmptyContext Ctx;
   Out.beginDocuments();
@@ -1866,8 +1853,7 @@ operator<<(Output &Out, T &Val) {
 
 // Provide better error message about types missing a trait specialization
 template <typename T>
-inline typename std::enable_if<missingTraits<T, EmptyContext>::value,
+inline std::enable_if_t<missingTraits<T, EmptyContext>::value, Output &>
-                               Output &>::type
 operator<<(Output &yout, T &seq) {
   char missing_yaml_trait_for_type[sizeof(MissingTrait<T>)];
   return yout;
@@ -1898,25 +1884,25 @@ template <bool> struct CheckIsBool { static const bool value = true; };
 // If T has SequenceElementTraits, then vector<T> and SmallVector<T, N> have
 // SequenceTraits that do the obvious thing.
 template <typename T>
-struct SequenceTraits<std::vector<T>,
+struct SequenceTraits<
-                      typename std::enable_if<CheckIsBool<
+    std::vector<T>,
-                          SequenceElementTraits<T>::flow>::value>::type>
+    std::enable_if_t<CheckIsBool<SequenceElementTraits<T>::flow>::value>>
     : SequenceTraitsImpl<std::vector<T>, SequenceElementTraits<T>::flow> {};
 template <typename T, unsigned N>
-struct SequenceTraits<SmallVector<T, N>,
+struct SequenceTraits<
-                      typename std::enable_if<CheckIsBool<
+    SmallVector<T, N>,
-                          SequenceElementTraits<T>::flow>::value>::type>
+    std::enable_if_t<CheckIsBool<SequenceElementTraits<T>::flow>::value>>
     : SequenceTraitsImpl<SmallVector<T, N>, SequenceElementTraits<T>::flow> {};
 template <typename T>
-struct SequenceTraits<SmallVectorImpl<T>,
+struct SequenceTraits<
-                      typename std::enable_if<CheckIsBool<
+    SmallVectorImpl<T>,
-                          SequenceElementTraits<T>::flow>::value>::type>
+    std::enable_if_t<CheckIsBool<SequenceElementTraits<T>::flow>::value>>
     : SequenceTraitsImpl<SmallVectorImpl<T>, SequenceElementTraits<T>::flow> {};
 
 // Sequences of fundamental types use flow formatting.
 template <typename T>
-struct SequenceElementTraits<
+struct SequenceElementTraits<T,
-    T, typename std::enable_if<std::is_fundamental<T>::value>::type> {
+                             std::enable_if_t<std::is_fundamental<T>::value>> {
   static const bool flow = true;
 };
 

include/llvm/Support/raw_ostream.h

@@ -358,9 +358,9 @@ private:
 /// Call the appropriate insertion operator, given an rvalue reference to a
 /// raw_ostream object and return a stream of the same type as the argument.
 template <typename OStream, typename T>
-typename std::enable_if<!std::is_reference<OStream>::value &&
+std::enable_if_t<!std::is_reference<OStream>::value &&
-                            std::is_base_of<raw_ostream, OStream>::value,
+                     std::is_base_of<raw_ostream, OStream>::value,
-                        OStream &&>::type
+                 OStream &&>
 operator<<(OStream &&OS, const T &Value) {
   OS << Value;
   return std::move(OS);

include/llvm/Support/type_traits.h

@@ -28,7 +28,7 @@ namespace llvm {
 /// Also note that enum classes aren't implicitly convertible to integral types,
 /// the value may therefore need to be explicitly converted before being used.
 template <typename T> class is_integral_or_enum {
-  using UnderlyingT = typename std::remove_reference<T>::type;
+  using UnderlyingT = std::remove_reference_t<T>;
 
 public:
   static const bool value =
@@ -45,7 +45,7 @@ struct add_lvalue_reference_if_not_pointer { using type = T &; };
 
 template <typename T>
 struct add_lvalue_reference_if_not_pointer<
-    T, typename std::enable_if<std::is_pointer<T>::value>::type> {
+    T, std::enable_if_t<std::is_pointer<T>::value>> {
   using type = T;
 };
 
@@ -55,9 +55,8 @@ template<typename T, typename Enable = void>
 struct add_const_past_pointer { using type = const T; };
 
 template <typename T>
-struct add_const_past_pointer<
+struct add_const_past_pointer<T, std::enable_if_t<std::is_pointer<T>::value>> {
-    T, typename std::enable_if<std::is_pointer<T>::value>::type> {
+  using type = const std::remove_pointer_t<T> *;
-  using type = const typename std::remove_pointer<T>::type *;
 };
 
 template <typename T, typename Enable = void>
@@ -65,8 +64,8 @@ struct const_pointer_or_const_ref {
   using type = const T &;
 };
 template <typename T>
-struct const_pointer_or_const_ref<
+struct const_pointer_or_const_ref<T,
-    T, typename std::enable_if<std::is_pointer<T>::value>::type> {
+                                  std::enable_if_t<std::is_pointer<T>::value>> {
   using type = typename add_const_past_pointer<T>::type;
 };
 

include/llvm/XRay/Graph.h

@@ -126,14 +126,14 @@ private:
   /// set.
   template <bool IsConst, bool IsOut,
             typename BaseIt = typename NeighborSetT::const_iterator,
-            typename T = typename std::conditional<IsConst, const EdgeValueType,
+            typename T =
-                                                   EdgeValueType>::type>
+                std::conditional_t<IsConst, const EdgeValueType, EdgeValueType>>
   class NeighborEdgeIteratorT
       : public iterator_adaptor_base<
             NeighborEdgeIteratorT<IsConst, IsOut>, BaseIt,
             typename std::iterator_traits<BaseIt>::iterator_category, T> {
     using InternalEdgeMapT =
-        typename std::conditional<IsConst, const EdgeMapT, EdgeMapT>::type;
+        std::conditional_t<IsConst, const EdgeMapT, EdgeMapT>;
 
     friend class NeighborEdgeIteratorT<false, IsOut, BaseIt, EdgeValueType>;
     friend class NeighborEdgeIteratorT<true, IsOut, BaseIt,
@@ -144,7 +144,7 @@ private:
 
   public:
     template <bool IsConstDest,
-              typename = typename std::enable_if<IsConstDest && !IsConst>::type>
+              typename = std::enable_if<IsConstDest && !IsConst>>
     operator NeighborEdgeIteratorT<IsConstDest, IsOut, BaseIt,
                                    const EdgeValueType>() const {
       return NeighborEdgeIteratorT<IsConstDest, IsOut, BaseIt,
@@ -199,9 +199,9 @@ public:
   public:
     using iterator = NeighborEdgeIteratorT<isConst, isOut>;
     using const_iterator = NeighborEdgeIteratorT<true, isOut>;
-    using GraphT = typename std::conditional<isConst, const Graph, Graph>::type;
+    using GraphT = std::conditional_t<isConst, const Graph, Graph>;
     using InternalEdgeMapT =
-        typename std::conditional<isConst, const EdgeMapT, EdgeMapT>::type;
+        std::conditional_t<isConst, const EdgeMapT, EdgeMapT>;
 
   private:
     InternalEdgeMapT &M;
@@ -272,10 +272,10 @@ public:
   /// the number of elements in the range and whether the range is empty.
   template <bool isConst> class VertexView {
   public:
-    using iterator = typename std::conditional<isConst, ConstVertexIterator,
+    using iterator =
-                                               VertexIterator>::type;
+        std::conditional_t<isConst, ConstVertexIterator, VertexIterator>;
     using const_iterator = ConstVertexIterator;
-    using GraphT = typename std::conditional<isConst, const Graph, Graph>::type;
+    using GraphT = std::conditional_t<isConst, const Graph, Graph>;
 
   private:
     GraphT &G;
@@ -309,10 +309,10 @@ public:
   /// the number of elements in the range and whether the range is empty.
   template <bool isConst> class EdgeView {
   public:
-    using iterator = typename std::conditional<isConst, ConstEdgeIterator,
+    using iterator =
-                                               EdgeIterator>::type;
+        std::conditional_t<isConst, ConstEdgeIterator, EdgeIterator>;
     using const_iterator = ConstEdgeIterator;
-    using GraphT = typename std::conditional<isConst, const Graph, Graph>::type;
+    using GraphT = std::conditional_t<isConst, const Graph, Graph>;
 
   private:
     GraphT &G;

lib/Demangle/ItaniumDemangle.cpp

@@ -107,13 +107,11 @@ struct DumpVisitor {
   // Overload used when T is exactly 'bool', not merely convertible to 'bool'.
   void print(bool B) { printStr(B ? "true" : "false"); }
 
-  template <class T>
+  template <class T> std::enable_if_t<std::is_unsigned<T>::value> print(T N) {
-  typename std::enable_if<std::is_unsigned<T>::value>::type print(T N) {
     fprintf(stderr, "%llu", (unsigned long long)N);
   }
 
-  template <class T>
+  template <class T> std::enable_if_t<std::is_signed<T>::value> print(T N) {
-  typename std::enable_if<std::is_signed<T>::value>::type print(T N) {
     fprintf(stderr, "%lld", (long long)N);
   }
 

lib/Support/ItaniumManglingCanonicalizer.cpp

@@ -30,9 +30,8 @@ struct FoldingSetNodeIDBuilder {
   void operator()(StringView Str) {
     ID.AddString(llvm::StringRef(Str.begin(), Str.size()));
   }
-  template<typename T>
+  template <typename T>
-  typename std::enable_if<std::is_integral<T>::value ||
+  std::enable_if_t<std::is_integral<T>::value || std::is_enum<T>::value>
-                          std::is_enum<T>::value>::type
   operator()(T V) {
     ID.AddInteger((unsigned long long)V);
   }

lib/Support/NativeFormatting.cpp

@@ -89,7 +89,7 @@ static void write_signed(raw_ostream &S, T N, size_t MinDigits,
                          IntegerStyle Style) {
   static_assert(std::is_signed<T>::value, "Value is not signed!");
 
-  using UnsignedT = typename std::make_unsigned<T>::type;
+  using UnsignedT = std::make_unsigned_t<T>;
 
   if (N >= 0) {
     write_unsigned(S, static_cast<UnsignedT>(N), MinDigits, Style);

lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp

@@ -757,8 +757,8 @@ public:
       return false;
 
     int64_t Val = MCE->getValue();
-    int64_t SVal = typename std::make_signed<T>::type(Val);
+    int64_t SVal = std::make_signed_t<T>(Val);
-    int64_t UVal = typename std::make_unsigned<T>::type(Val);
+    int64_t UVal = std::make_unsigned_t<T>(Val);
     if (Val != SVal && Val != UVal)
       return false;
 
@@ -854,8 +854,7 @@ public:
     if (!isShiftedImm() && (!isImm() || !isa<MCConstantExpr>(getImm())))
       return DiagnosticPredicateTy::NoMatch;
 
-    bool IsByte =
+    bool IsByte = std::is_same<int8_t, std::make_signed_t<T>>::value;
-        std::is_same<int8_t, typename std::make_signed<T>::type>::value;
     if (auto ShiftedImm = getShiftedVal<8>())
       if (!(IsByte && ShiftedImm->second) &&
           AArch64_AM::isSVECpyImm<T>(uint64_t(ShiftedImm->first)
@@ -872,8 +871,7 @@ public:
     if (!isShiftedImm() && (!isImm() || !isa<MCConstantExpr>(getImm())))
       return DiagnosticPredicateTy::NoMatch;
 
-    bool IsByte =
+    bool IsByte = std::is_same<int8_t, std::make_signed_t<T>>::value;
-        std::is_same<int8_t, typename std::make_signed<T>::type>::value;
     if (auto ShiftedImm = getShiftedVal<8>())
       if (!(IsByte && ShiftedImm->second) &&
           AArch64_AM::isSVEAddSubImm<T>(ShiftedImm->first
@@ -1610,7 +1608,7 @@ public:
   void addLogicalImmOperands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");
     const MCConstantExpr *MCE = cast<MCConstantExpr>(getImm());
-    typename std::make_unsigned<T>::type Val = MCE->getValue();
+    std::make_unsigned_t<T> Val = MCE->getValue();
     uint64_t encoding = AArch64_AM::encodeLogicalImmediate(Val, sizeof(T) * 8);
     Inst.addOperand(MCOperand::createImm(encoding));
   }
@@ -1619,7 +1617,7 @@ public:
   void addLogicalImmNotOperands(MCInst &Inst, unsigned N) const {
     assert(N == 1 && "Invalid number of operands!");
     const MCConstantExpr *MCE = cast<MCConstantExpr>(getImm());
-    typename std::make_unsigned<T>::type Val = ~MCE->getValue();
+    std::make_unsigned_t<T> Val = ~MCE->getValue();
     uint64_t encoding = AArch64_AM::encodeLogicalImmediate(Val, sizeof(T) * 8);
     Inst.addOperand(MCOperand::createImm(encoding));
   }

lib/Target/AArch64/MCTargetDesc/AArch64AddressingModes.h

@@ -763,10 +763,10 @@ static inline bool isSVECpyImm(int64_t Imm) {
   bool IsImm8 = int8_t(Imm) == Imm;
   bool IsImm16 = int16_t(Imm & ~0xff) == Imm;
 
-  if (std::is_same<int8_t, typename std::make_signed<T>::type>::value)
+  if (std::is_same<int8_t, std::make_signed_t<T>>::value)
     return IsImm8 || uint8_t(Imm) == Imm;
 
-  if (std::is_same<int16_t, typename std::make_signed<T>::type>::value)
+  if (std::is_same<int16_t, std::make_signed_t<T>>::value)
     return IsImm8 || IsImm16 || uint16_t(Imm & ~0xff) == Imm;
 
   return IsImm8 || IsImm16;
@@ -775,8 +775,7 @@ static inline bool isSVECpyImm(int64_t Imm) {
 /// Returns true if Imm is valid for ADD/SUB.
 template <typename T>
 static inline bool isSVEAddSubImm(int64_t Imm) {
-  bool IsInt8t =
+  bool IsInt8t = std::is_same<int8_t, std::make_signed_t<T>>::value;
-      std::is_same<int8_t, typename std::make_signed<T>::type>::value;
   return uint8_t(Imm) == Imm || (!IsInt8t && uint16_t(Imm & ~0xff) == Imm);
 }
 

lib/Target/AArch64/MCTargetDesc/AArch64InstPrinter.cpp

@@ -1511,7 +1511,7 @@ void AArch64InstPrinter::printSVERegOp(const MCInst *MI, unsigned OpNum,
 
 template <typename T>
 void AArch64InstPrinter::printImmSVE(T Value, raw_ostream &O) {
-  typename std::make_unsigned<T>::type HexValue = Value;
+  std::make_unsigned_t<T> HexValue = Value;
 
   if (getPrintImmHex())
     O << '#' << formatHex((uint64_t)HexValue);
@@ -1556,8 +1556,8 @@ template <typename T>
 void AArch64InstPrinter::printSVELogicalImm(const MCInst *MI, unsigned OpNum,
                                             const MCSubtargetInfo &STI,
                                             raw_ostream &O) {
-  typedef typename std::make_signed<T>::type SignedT;
+  typedef std::make_signed_t<T> SignedT;
-  typedef typename std::make_unsigned<T>::type UnsignedT;
+  typedef std::make_unsigned_t<T> UnsignedT;
 
   uint64_t Val = MI->getOperand(OpNum).getImm();
   UnsignedT PrintVal = AArch64_AM::decodeLogicalImmediate(Val, 64);

lib/XRay/FDRTraceWriter.cpp

@@ -20,10 +20,9 @@ namespace {
 template <size_t Index> struct IndexedWriter {
   template <
       class Tuple,
-      typename std::enable_if<
+      std::enable_if_t<(Index <
-          (Index <
+                        std::tuple_size<std::remove_reference_t<Tuple>>::value),
-           std::tuple_size<typename std::remove_reference<Tuple>::type>::value),
+                       int> = 0>
-          int>::type = 0>
   static size_t write(support::endian::Writer &OS, Tuple &&T) {
     OS.write(std::get<Index>(T));
     return sizeof(std::get<Index>(T)) + IndexedWriter<Index + 1>::write(OS, T);
@@ -31,10 +30,9 @@ template <size_t Index> struct IndexedWriter {
 
   template <
       class Tuple,
-      typename std::enable_if<
+      std::enable_if_t<(Index >=
-          (Index >=
+                        std::tuple_size<std::remove_reference_t<Tuple>>::value),
-           std::tuple_size<typename std::remove_reference<Tuple>::type>::value),
+                       int> = 0>
-          int>::type = 0>
   static size_t write(support::endian::Writer &OS, Tuple &&) {
     return 0;
   }

tools/dsymutil/CFBundle.cpp

@@ -34,9 +34,8 @@ template <typename T> struct CFDeleter {
 /// any valid pointer it owns unless that pointer is explicitly released using
 /// the release() member function.
 template <typename T>
-using CFReleaser =
+using CFReleaser = std::unique_ptr<std::remove_pointer_t<T>,
-    std::unique_ptr<typename std::remove_pointer<T>::type,
+                                   CFDeleter<std::remove_pointer_t<T>>>;
-                    CFDeleter<typename std::remove_pointer<T>::type>>;
 
 /// RAII wrapper around CFBundleRef.
 class CFString : public CFReleaser<CFStringRef> {

tools/llvm-pdbutil/FormatUtil.h

@@ -42,8 +42,7 @@ std::string truncateQuotedNameBack(StringRef Label, StringRef Name,
     return Ret;
 
 template <typename T> std::string formatUnknownEnum(T Value) {
-  return formatv("unknown ({0})",
+  return formatv("unknown ({0})", static_cast<std::underlying_type_t<T>>(Value))
-                 static_cast<typename std::underlying_type<T>::type>(Value))
       .str();
 }
 

tools/llvm-xray/trie-node.h

@@ -48,7 +48,7 @@ template <typename T, typename Callable>
 TrieNode<T> *
 mergeTrieNodes(const TrieNode<T> &Left, const TrieNode<T> &Right,
                /*Non-deduced pointer type for nullptr compatibility*/
-               typename std::remove_reference<TrieNode<T> *>::type NewParent,
+               std::remove_reference_t<TrieNode<T> *> NewParent,
                std::forward_list<TrieNode<T>> &NodeStore,
                Callable &&MergeCallable) {
   llvm::function_ref<T(const T &, const T &)> MergeFn(

unittests/ADT/DenseSetTest.cpp

@@ -52,7 +52,7 @@ protected:
 
 private:
   static T GetTestSet() {
-    typename std::remove_const<T>::type Set;
+    std::remove_const_t<T> Set;
     Set.insert(0);
     Set.insert(1);
     Set.insert(2);

unittests/IR/PatternMatch.cpp

@@ -1319,8 +1319,8 @@ TYPED_TEST_CASE(MutableConstTest, MutableConstTestTypes);
 TYPED_TEST(MutableConstTest, ICmp) {
   auto &IRB = PatternMatchTest::IRB;
 
-  typedef typename std::tuple_element<0, TypeParam>::type ValueType;
+  typedef std::tuple_element_t<0, TypeParam> ValueType;
-  typedef typename std::tuple_element<1, TypeParam>::type InstructionType;
+  typedef std::tuple_element_t<1, TypeParam> InstructionType;
 
   Value *L = IRB.getInt32(1);
   Value *R = IRB.getInt32(2);

unittests/XRay/GraphTest.cpp

@@ -34,7 +34,7 @@ protected:
 private:
   static T getTestGraph() {
     using std::make_pair;
-    typename std::remove_const<T>::type G;
+    std::remove_const_t<T> G;
     G.insert(make_pair(1u, VAttr({3u})));
     G.insert(make_pair(2u, VAttr({5u})));
     G.insert(make_pair(3u, VAttr({7u})));

utils/benchmark/include/benchmark/benchmark.h

@@ -990,8 +990,7 @@ inline internal::Benchmark* RegisterBenchmark(const char* name,
 #ifdef BENCHMARK_HAS_CXX11
 template <class Lambda>
 internal::Benchmark* RegisterBenchmark(const char* name, Lambda&& fn) {
-  using BenchType =
+  using BenchType = internal::LambdaBenchmark<std::decay_t<Lambda>>;
-      internal::LambdaBenchmark<typename std::decay<Lambda>::type>;
   return internal::RegisterBenchmarkInternal(
       ::new BenchType(name, std::forward<Lambda>(fn)));
 }

utils/benchmark/src/sysinfo.cc

@@ -176,9 +176,8 @@ bool GetSysctl(std::string const& Name, std::string* Out) {
   return true;
 }
 
-template <class Tp,
+template <class Tp, class = std::enable_if_t<std::is_integral<Tp>::value>>
-          class = typename std::enable_if<std::is_integral<Tp>::value>::type>
+bool GetSysctl(std::string const &Name, Tp *Out) {
-bool GetSysctl(std::string const& Name, Tp* Out) {
   *Out = 0;
   auto Buff = GetSysctlImp(Name);
   if (!Buff) return false;

utils/unittest/googlemock/include/gmock/gmock-matchers.h

@@ -3118,8 +3118,9 @@ class ElementsAreMatcherImpl : public MatcherInterface<Container> {
   typedef typename View::const_reference StlContainerReference;
   typedef decltype(std::begin(
       std::declval<StlContainerReference>())) StlContainerConstIterator;
-  typedef typename std::remove_reference<decltype(
+  typedef std::remove_reference_t<decltype(
-      *std::declval<StlContainerConstIterator &>())>::type Element;
+      *std::declval<StlContainerConstIterator &>())>
+      Element;
 
   // Constructs the matcher from a sequence of element values or
   // element matchers.
@@ -3360,8 +3361,9 @@ class UnorderedElementsAreMatcherImpl
   typedef typename View::const_reference StlContainerReference;
   typedef decltype(std::begin(
       std::declval<StlContainerReference>())) StlContainerConstIterator;
-  typedef typename std::remove_reference<decltype(
+  typedef std::remove_reference_t<decltype(
-      *std::declval<StlContainerConstIterator &>())>::type Element;
+      *std::declval<StlContainerConstIterator &>())>
+      Element;
 
   // Constructs the matcher from a sequence of element values or
   // element matchers.
@@ -3470,8 +3472,9 @@ class UnorderedElementsAreMatcher {
     typedef typename View::const_reference StlContainerReference;
     typedef decltype(std::begin(
         std::declval<StlContainerReference>())) StlContainerConstIterator;
-    typedef typename std::remove_reference<decltype(
+    typedef std::remove_reference_t<decltype(
-        *std::declval<StlContainerConstIterator &>())>::type Element;
+        *std::declval<StlContainerConstIterator &>())>
+        Element;
     typedef ::std::vector<Matcher<const Element&> > MatcherVec;
     MatcherVec matchers;
     matchers.reserve(::testing::tuple_size<MatcherTuple>::value);
@@ -3499,8 +3502,9 @@ class ElementsAreMatcher {
     typedef typename View::const_reference StlContainerReference;
     typedef decltype(std::begin(
         std::declval<StlContainerReference>())) StlContainerConstIterator;
-    typedef typename std::remove_reference<decltype(
+    typedef std::remove_reference_t<decltype(
-        *std::declval<StlContainerConstIterator &>())>::type Element;
+        *std::declval<StlContainerConstIterator &>())>
+        Element;
     typedef ::std::vector<Matcher<const Element&> > MatcherVec;
     MatcherVec matchers;
     matchers.reserve(::testing::tuple_size<MatcherTuple>::value);