This can be used for in-place initialization of non-moveable types.
For compilers that don't support variadic templates, only up to four
arguments are supported. We can always add more, of course, but this
should be good enough until we move to a later MSVC that has full
support for variadic templates.
Inspired by std::experimental::optional from the "Library Fundamentals" C++ TS.
Reviewed by David Blaikie.
llvm-svn: 218732
This takes a single argument convertible to T, and
- if the Optional has a value, returns the existing value,
- otherwise, constructs a T from the argument and returns that.
Inspired by std::experimental::optional from the "Library Fundamentals" C++ TS.
llvm-svn: 218618
It's not clear what the semantics of a self-move should be. The
consensus appears to be that a self-move should leave the object in a
moved-from state, which is what our existing move assignment operator
does.
However, the MSVC 2013 STL will perform self-moves in some cases. In
particular, when doing a std::stable_sort of an already sorted APSInt
vector of an appropriate size, one of the merge steps will self-move
half of the elements.
We don't notice this when building with MSVC, because MSVC will not
synthesize the move assignment operator for APSInt. Presumably MSVC
does this because APInt, the base class, has user-declared special
members that implicitly delete move special members. Instead, MSVC
selects the copy-assign operator, which defends against self-assignment.
Clang, on the other hand, selects the move-assign operator, and we get
garbage APInts.
llvm-svn: 215478
Remove the MinGW32 and Cygwin types from the OSType enumeration. These values
are represented via environments of Windows. It is a source of confusion and
needlessly clutters the code. The cost of doing this is that we must sink the
check for them into the normalization code path along with the spelling.
Addresses PR20592.
llvm-svn: 215303
checking whether the ArrayRef is equal to an explicit list of arguments.
This is particularly easy to implement even without variadic templates
because ArrayRef happens to be homogeneously typed. As a consequence we
can use a "clever" wrapper type and default arguments to capture in
a single method many arguments as well as *how many* arguments the user
specified.
Thanks to Dave Blaikie for helping me pull together this little helper.
Suggestions for how to improve or generalize it are of course welcome.
I'll be using it immediately in my follow-up patch. =D
llvm-svn: 214041
Add a `MapVector::remove_if()` that erases items in bulk in linear time,
as opposed to quadratic time for repeated calls to `MapVector::erase()`.
llvm-svn: 213090
Actually update the changed indexes in the map portion of `MapVector`
when erasing from the middle. Add a unit test that checks for this.
Note that `MapVector::erase()` is a linear time operation (it was and
still is). I'll commit a new method in a moment called
`MapVector::remove_if()` that deletes multiple entries in linear time,
which should be slightly less painful.
llvm-svn: 213084
The slice(N, M) interface is powerful but not concise when wanting to
drop a few elements off of an ArrayRef, fix this by adding a drop_back
method.
llvm-svn: 212370
Certain versions of GCC (~4.7) couldn't handle the SFINAE on access
control, but with "= delete" (hidden behind a macro for portability)
this issue is worked around/addressed.
Patch by Agustín Bergé
llvm-svn: 211525
Unfortunately there's no way to elegantly do this with pre-canned
algorithms. Using a generating iterator doesn't work because you default
construct for each element, then move construct into the actual slot
(bad for copy but non-movable types, and a little unneeded overhead even
in the move-only case), so just write it out manually.
This solution isn't exception safe (if one of the element's ctors calls
we don't fall back, destroy the constructed elements, and throw on -
which std::uninitialized_fill does do) but SmallVector (and LLVM) isn't
exception safe anyway.
llvm-svn: 210495
To test cases that involve actual repetition (> 1 elements), at least
one element before the insertion point, and some elements of the
original range that still fit in that range space after insertion.
Actually we need coverage for the inverse case too (where no elements
after the insertion point fit into the previously allocated space), but
this'll do for now, and I might end up rewriting bits of SmallVector to
avoid that special case anyway.
llvm-svn: 210436
Specifically this caused inserting an element from a SmallVector into
itself when such an insertion would cause a reallocation. We have code
to handle this for non-reallocating cases, but it's not robust against
reallocation.
llvm-svn: 210430
(& because it makes it easier to test, this also improves
correctness/performance slightly by moving the last element in an insert
operation, rather than copying it)
llvm-svn: 210429
Because we don't have a separate negate( ) function, 0 - NaN does double-duty as the IEEE-754 negate( ) operation, which (unlike most FP ops) *does* attach semantic meaning to the signbit of NaN.
llvm-svn: 210428
This would cause the last element in a range to be in a moved-from state
after an insert at a non-end position, losing that value entirely in the
process.
Side note: move_backward is subtle. It copies [A, B) to C-1 and down.
(the fact that it decrements both the second and third iterators before
the first movement is the subtle part... kind of surprising, anyway)
llvm-svn: 210426
When we were moving from a larger vector to a smaller one but didn't
need to re-allocate, we would move-assign over uninitialized memory in
the target, then move-construct that same data again.
llvm-svn: 207663
It's fishy to be changing the `std::vector<>` owned by the iterator, and
no one actual does it, so I'm going to remove the ability in a
subsequent commit. First, update the users.
<rdar://problem/14292693>
llvm-svn: 207252
This generalises the object file type parsing to all Windows environments. This
is used by cygwin as well as MSVC environments for MCJIT. This also makes the
triple more similar to Chandler's suggestion of a separate field for the object
file format.
llvm-svn: 205219
