RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-24 03:33:20 +01:00
Code Issues Projects Releases Wiki Activity

Add next() and prior() iterator utility functions. Unlike std::advance

Browse Source 
they do not modify the passed iterator but return a copy.

next(myIt) returns copy of myIt incremented once
next(myIt, n) returns copy of myIt incremented n times
prior(myIt) returns copy of myIt decremented once
prior(myIt, n) returns copy of myIt decremented n times

While at it remove obsolete implementation of mapped_iterator.

llvm-svn: 11429
This commit is contained in:
Alkis Evlogimenos 2004-02-14 01:17:28 +00:00
parent 15229988fb
commit fa9e207a22
1 changed files with 37 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

60
include/Support/STLExtras.h
View File

@ -75,7 +75,6 @@ static inline void deleter(T *Ptr) {
//
// It turns out that this is disturbingly similar to boost::transform_iterator
//
#if 1
template <class RootIt, class UnaryFunc>
class mapped_iterator {
RootIt current;
@ -131,28 +130,6 @@ operator+(typename mapped_iterator<_Iterator, Func>::difference_type N,
return mapped_iterator<_Iterator, Func>(X.getCurrent() - N);
}
#else
// This fails to work, because some iterators are not classes, for example
// vector iterators are commonly value_type **'s
template <class RootIt, class UnaryFunc>
class mapped_iterator : public RootIt {
UnaryFunc Fn;
public:
typedef typename UnaryFunc::result_type value_type;
typedef typename UnaryFunc::result_type *pointer;
typedef void reference; // Can't modify value returned by fn
typedef mapped_iterator<RootIt, UnaryFunc> _Self;
typedef RootIt super;
inline explicit mapped_iterator(const RootIt &I) : super(I) {}
inline mapped_iterator(const super &It) : super(It) {}
inline value_type operator*() const { // All this work to do
return Fn(super::operator*()); // this little thing
}
};
#endif
// map_iterator - Provide a convenient way to create mapped_iterators, just like
// make_pair is useful for creating pairs...
@ -163,6 +140,43 @@ inline mapped_iterator<ItTy, FuncTy> map_iterator(const ItTy &I, FuncTy F) {
}
// next/prior - These functions unlike std::advance do not modify the
// passed iterator but return a copy.
//
// next(myIt) returns copy of myIt incremented once
// next(myIt, n) returns copy of myIt incremented n times
// prior(myIt) returns copy of myIt decremented once
// prior(myIt, n) returns copy of myIt decremented n times
template <typename ItTy, typename Dist>
inline ItTy next(ItTy it, Dist n)
{
std::advance(it, n);
return it;
}
template <typename ItTy>
inline ItTy next(ItTy it)
{
std::advance(it, 1);
return it;
}
template <typename ItTy, typename Dist>
inline ItTy prior(ItTy it, Dist n)
{
std::advance(it, -n);
return it;
}
template <typename ItTy>
inline ItTy prior(ItTy it)
{
std::advance(it, -1);
return it;
}
//===----------------------------------------------------------------------===//
// Extra additions to <algorithm>
//===----------------------------------------------------------------------===//