mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-26 12:43:36 +01:00
0494b1028d
Summary: The instantiation of the drop_begin function template usually fails because the functions begin() and end() do not exist. Only when using on a container from the std namespace (or `llvm::iterator_range`s of something derived from `std::iterator`), they are matched to std::begin() and std::end() due to Koenig-lookup. Explicitly use llvm::adl_begin and llvm::adl_end to make drop_begin applicable to anything iterable (including C-style arrays). A solution for general `llvm::iterator_range`s was already tried in r244620, but got reverted in r244621 due to MSVC not liking it. Reviewers: dblaikie, grosbach, aaron.ballman, ruiu Reviewed By: dblaikie, aaron.ballman Subscribers: aaron.ballman, llvm-commits Differential Revision: https://reviews.llvm.org/D48598 llvm-svn: 335772
70 lines
2.4 KiB
C++
70 lines
2.4 KiB
C++
//===- iterator_range.h - A range adaptor for iterators ---------*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
/// \file
|
|
/// This provides a very simple, boring adaptor for a begin and end iterator
|
|
/// into a range type. This should be used to build range views that work well
|
|
/// with range based for loops and range based constructors.
|
|
///
|
|
/// Note that code here follows more standards-based coding conventions as it
|
|
/// is mirroring proposed interfaces for standardization.
|
|
///
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_ADT_ITERATOR_RANGE_H
|
|
#define LLVM_ADT_ITERATOR_RANGE_H
|
|
|
|
#include <iterator>
|
|
#include <utility>
|
|
|
|
namespace llvm {
|
|
|
|
/// A range adaptor for a pair of iterators.
|
|
///
|
|
/// This just wraps two iterators into a range-compatible interface. Nothing
|
|
/// fancy at all.
|
|
template <typename IteratorT>
|
|
class iterator_range {
|
|
IteratorT begin_iterator, end_iterator;
|
|
|
|
public:
|
|
//TODO: Add SFINAE to test that the Container's iterators match the range's
|
|
// iterators.
|
|
template <typename Container>
|
|
iterator_range(Container &&c)
|
|
//TODO: Consider ADL/non-member begin/end calls.
|
|
: begin_iterator(c.begin()), end_iterator(c.end()) {}
|
|
iterator_range(IteratorT begin_iterator, IteratorT end_iterator)
|
|
: begin_iterator(std::move(begin_iterator)),
|
|
end_iterator(std::move(end_iterator)) {}
|
|
|
|
IteratorT begin() const { return begin_iterator; }
|
|
IteratorT end() const { return end_iterator; }
|
|
};
|
|
|
|
/// Convenience function for iterating over sub-ranges.
|
|
///
|
|
/// This provides a bit of syntactic sugar to make using sub-ranges
|
|
/// in for loops a bit easier. Analogous to std::make_pair().
|
|
template <class T> iterator_range<T> make_range(T x, T y) {
|
|
return iterator_range<T>(std::move(x), std::move(y));
|
|
}
|
|
|
|
template <typename T> iterator_range<T> make_range(std::pair<T, T> p) {
|
|
return iterator_range<T>(std::move(p.first), std::move(p.second));
|
|
}
|
|
|
|
template <typename T>
|
|
iterator_range<decltype(adl_begin(std::declval<T>()))> drop_begin(T &&t,
|
|
int n) {
|
|
return make_range(std::next(adl_begin(t), n), adl_end(t));
|
|
}
|
|
}
|
|
|
|
#endif
|