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libcxx/test/std/iterators/iterator.primitives/iterator.operations/advance.pass.cpp

73 lines
2.7 KiB
C++

//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <iterator>
// All of these became constexpr in C++17
//
// template <InputIterator Iter>
// constexpr void advance(Iter& i, Iter::difference_type n);
//
// template <BidirectionalIterator Iter>
// constexpr void advance(Iter& i, Iter::difference_type n);
//
// template <RandomAccessIterator Iter>
// constexpr void advance(Iter& i, Iter::difference_type n);
#include <iterator>
#include <cassert>
#include "test_iterators.h"
template <class It>
void
test(It i, typename std::iterator_traits<It>::difference_type n, It x)
{
std::advance(i, n);
assert(i == x);
}
#if TEST_STD_VER > 14
template <class It>
constexpr bool
constepxr_test(It i, typename std::iterator_traits<It>::difference_type n, It x)
{
std::advance(i, n);
return i == x;
}
#endif
int main()
{
{
const char* s = "1234567890";
test(input_iterator<const char*>(s), 10, input_iterator<const char*>(s+10));
test(forward_iterator<const char*>(s), 10, forward_iterator<const char*>(s+10));
test(bidirectional_iterator<const char*>(s+5), 5, bidirectional_iterator<const char*>(s+10));
test(bidirectional_iterator<const char*>(s+5), -5, bidirectional_iterator<const char*>(s));
test(random_access_iterator<const char*>(s+5), 5, random_access_iterator<const char*>(s+10));
test(random_access_iterator<const char*>(s+5), -5, random_access_iterator<const char*>(s));
test(s+5, 5, s+10);
test(s+5, -5, s);
}
#if TEST_STD_VER > 14
{
constexpr const char* s = "1234567890";
static_assert( constepxr_test(input_iterator<const char*>(s), 10, input_iterator<const char*>(s+10)), "" );
static_assert( constepxr_test(forward_iterator<const char*>(s), 10, forward_iterator<const char*>(s+10)), "" );
static_assert( constepxr_test(bidirectional_iterator<const char*>(s+5), 5, bidirectional_iterator<const char*>(s+10)), "" );
static_assert( constepxr_test(bidirectional_iterator<const char*>(s+5), -5, bidirectional_iterator<const char*>(s)), "" );
static_assert( constepxr_test(random_access_iterator<const char*>(s+5), 5, random_access_iterator<const char*>(s+10)), "" );
static_assert( constepxr_test(random_access_iterator<const char*>(s+5), -5, random_access_iterator<const char*>(s)), "" );
static_assert( constepxr_test(s+5, 5, s+10), "" );
static_assert( constepxr_test(s+5, -5, s), "" );
}
#endif
}