//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// <span>
// template<size_t Offset, size_t Count = dynamic_extent>
// constexpr span<element_type, see below> subspan() const;
//
// constexpr span<element_type, dynamic_extent> subspan(
// size_type offset, size_type count = dynamic_extent) const;
//
// Mandates: Offset <= Extent && (Count == dynamic_extent || Count <= Extent - Offset) is true.
#include <span>
#include <cassert>
#include <algorithm>
#include <string>
#include "test_macros.h"
template <typename Span, std::size_t Offset, size_t Count>
constexpr bool testConstexprSpan(Span sp)
{
LIBCPP_ASSERT((noexcept(sp.template subspan<Offset, Count>())));
LIBCPP_ASSERT((noexcept(sp.subspan(Offset, Count))));
auto s1 = sp.template subspan<Offset, Count>();
auto s2 = sp.subspan(Offset, Count);
using S1 = decltype(s1);
using S2 = decltype(s2);
ASSERT_SAME_TYPE(typename Span::value_type, typename S1::value_type);
ASSERT_SAME_TYPE(typename Span::value_type, typename S2::value_type);
static_assert(S1::extent == Count);
static_assert(S2::extent == std::dynamic_extent, "");
return
s1.data() == s2.data()
&& s1.size() == s2.size()
&& std::equal(s1.begin(), s1.end(), sp.begin() + Offset);
}
template <typename Span, std::size_t Offset>
constexpr bool testConstexprSpan(Span sp)
{
LIBCPP_ASSERT((noexcept(sp.template subspan<Offset>())));
LIBCPP_ASSERT((noexcept(sp.subspan(Offset))));
auto s1 = sp.template subspan<Offset>();
auto s2 = sp.subspan(Offset);
using S1 = decltype(s1);
using S2 = decltype(s2);
ASSERT_SAME_TYPE(typename Span::value_type, typename S1::value_type);
ASSERT_SAME_TYPE(typename Span::value_type, typename S2::value_type);
static_assert(S1::extent == (Span::extent == std::dynamic_extent ? std::dynamic_extent : Span::extent - Offset), "");
static_assert(S2::extent == std::dynamic_extent, "");
return
s1.data() == s2.data()
&& s1.size() == s2.size()
&& std::equal(s1.begin(), s1.end(), sp.begin() + Offset, sp.end());
}
template <typename Span, std::size_t Offset, size_t Count>
void testRuntimeSpan(Span sp)
{
LIBCPP_ASSERT((noexcept(sp.template subspan<Offset, Count>())));
LIBCPP_ASSERT((noexcept(sp.subspan(Offset, Count))));
auto s1 = sp.template subspan<Offset, Count>();
auto s2 = sp.subspan(Offset, Count);
using S1 = decltype(s1);
using S2 = decltype(s2);
ASSERT_SAME_TYPE(typename Span::value_type, typename S1::value_type);
ASSERT_SAME_TYPE(typename Span::value_type, typename S2::value_type);
static_assert(S1::extent == Count);
static_assert(S2::extent == std::dynamic_extent, "");
assert(s1.data() == s2.data());
assert(s1.size() == s2.size());
assert(std::equal(s1.begin(), s1.end(), sp.begin() + Offset));
}
template <typename Span, std::size_t Offset>
void testRuntimeSpan(Span sp)
{
LIBCPP_ASSERT((noexcept(sp.template subspan<Offset>())));
LIBCPP_ASSERT((noexcept(sp.subspan(Offset))));
auto s1 = sp.template subspan<Offset>();
auto s2 = sp.subspan(Offset);
using S1 = decltype(s1);
using S2 = decltype(s2);
ASSERT_SAME_TYPE(typename Span::value_type, typename S1::value_type);
ASSERT_SAME_TYPE(typename Span::value_type, typename S2::value_type);
static_assert(S1::extent == (Span::extent == std::dynamic_extent ? std::dynamic_extent : Span::extent - Offset), "");
static_assert(S2::extent == std::dynamic_extent, "");
assert(s1.data() == s2.data());
assert(s1.size() == s2.size());
assert(std::equal(s1.begin(), s1.end(), sp.begin() + Offset, sp.end()));
}
constexpr int carr1[] = {1,2,3,4};
int arr1[] = {5,6,7};
int main(int, char**)
{
{
using Sp = std::span<const int>;
static_assert(testConstexprSpan<Sp, 0>(Sp{}), "");
static_assert(testConstexprSpan<Sp, 0, 4>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 0, 3>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 0, 2>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 0, 1>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 0, 0>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 1, 3>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 2, 2>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 3, 1>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 4, 0>(Sp{carr1}), "");
}
{
using Sp = std::span<const int, 4>;
static_assert(testConstexprSpan<Sp, 0, 4>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 0, 3>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 0, 2>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 0, 1>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 0, 0>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 1, 3>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 2, 2>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 3, 1>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 4, 0>(Sp{carr1}), "");
}
{
using Sp = std::span<const int>;
static_assert(testConstexprSpan<Sp, 0>(Sp{}), "");
static_assert(testConstexprSpan<Sp, 0>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 1>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 2>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 3>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 4>(Sp{carr1}), "");
}
{
using Sp = std::span<const int, 4>;
static_assert(testConstexprSpan<Sp, 0>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 1>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 2>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 3>(Sp{carr1}), "");
static_assert(testConstexprSpan<Sp, 4>(Sp{carr1}), "");
}
{
using Sp = std::span<int>;
testRuntimeSpan<Sp, 0>(Sp{});
testRuntimeSpan<Sp, 0, 3>(Sp{arr1});
testRuntimeSpan<Sp, 0, 2>(Sp{arr1});
testRuntimeSpan<Sp, 0, 1>(Sp{arr1});
testRuntimeSpan<Sp, 0, 0>(Sp{arr1});
testRuntimeSpan<Sp, 1, 2>(Sp{arr1});
testRuntimeSpan<Sp, 2, 1>(Sp{arr1});
testRuntimeSpan<Sp, 3, 0>(Sp{arr1});
}
{
using Sp = std::span<int, 3>;
testRuntimeSpan<Sp, 0, 3>(Sp{arr1});
testRuntimeSpan<Sp, 0, 2>(Sp{arr1});
testRuntimeSpan<Sp, 0, 1>(Sp{arr1});
testRuntimeSpan<Sp, 0, 0>(Sp{arr1});
testRuntimeSpan<Sp, 1, 2>(Sp{arr1});
testRuntimeSpan<Sp, 2, 1>(Sp{arr1});
testRuntimeSpan<Sp, 3, 0>(Sp{arr1});
}
{
using Sp = std::span<int>;
testRuntimeSpan<Sp, 0>(Sp{});
testRuntimeSpan<Sp, 0>(Sp{arr1});
testRuntimeSpan<Sp, 1>(Sp{arr1});
testRuntimeSpan<Sp, 2>(Sp{arr1});
testRuntimeSpan<Sp, 3>(Sp{arr1});
}
{
using Sp = std::span<int, 3>;
testRuntimeSpan<Sp, 0>(Sp{arr1});
testRuntimeSpan<Sp, 1>(Sp{arr1});
testRuntimeSpan<Sp, 2>(Sp{arr1});
testRuntimeSpan<Sp, 3>(Sp{arr1});
}
return 0;
}
Codebase Browser
llvm