//===----------------------------------------------------------------------===//
//
// 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>
// constexpr span& operator=(const span& other) noexcept = default;
#include <span>
#include <cassert>
#include <iterator>
#include <string>
#include <utility>
#include "test_macros.h"
template <typename T>
constexpr bool doAssign(T lhs, T rhs)
{
ASSERT_NOEXCEPT(std::declval<T&>() = rhs);
lhs = rhs;
return lhs.data() == rhs.data()
&& lhs.size() == rhs.size();
}
struct A{};
constexpr int carr1[] = {1,2,3,4};
constexpr int carr2[] = {3,4,5};
constexpr int carr3[] = {7,8};
int arr[] = {5,6,7,9};
std::string strs[] = {"ABC", "DEF", "GHI"};
int main(int, char**)
{
// constexpr dynamically sized assignment
{
// On systems where 'ptrdiff_t' is a synonym for 'int',
// the call span(ptr, 0) selects the (pointer, size_type) constructor.
// On systems where 'ptrdiff_t' is NOT a synonym for 'int',
// it is ambiguous, because of 0 also being convertible to a null pointer
// and so the compiler can't choose between:
// span(pointer, size_type)
// and span(pointer, pointer)
// We cast zero to std::ptrdiff_t to remove that ambiguity.
// Example:
// On darwin x86_64, ptrdiff_t is the same as long int.
// On darwin i386, ptrdiff_t is the same as int.
constexpr std::span<const int> spans[] = {
{},
{carr1, static_cast<std::size_t>(0)},
{carr1, 1U},
{carr1, 2U},
{carr1, 3U},
{carr1, 4U},
{carr2, static_cast<std::size_t>(0)},
{carr2, 1U},
{carr2, 2U},
{carr2, 3U},
{carr3, static_cast<std::size_t>(0)},
{carr3, 1U},
{carr3, 2U}
};
static_assert(std::size(spans) == 13, "" );
// No for loops in constexpr land :-(
static_assert(doAssign(spans[0], spans[0]), "");
static_assert(doAssign(spans[0], spans[1]), "");
static_assert(doAssign(spans[0], spans[2]), "");
static_assert(doAssign(spans[0], spans[3]), "");
static_assert(doAssign(spans[0], spans[4]), "");
static_assert(doAssign(spans[0], spans[5]), "");
static_assert(doAssign(spans[0], spans[6]), "");
static_assert(doAssign(spans[0], spans[7]), "");
static_assert(doAssign(spans[0], spans[8]), "");
static_assert(doAssign(spans[0], spans[9]), "");
static_assert(doAssign(spans[0], spans[10]), "");
static_assert(doAssign(spans[0], spans[11]), "");
static_assert(doAssign(spans[0], spans[12]), "");
static_assert(doAssign(spans[1], spans[1]), "");
static_assert(doAssign(spans[1], spans[2]), "");
static_assert(doAssign(spans[1], spans[3]), "");
static_assert(doAssign(spans[1], spans[4]), "");
static_assert(doAssign(spans[1], spans[5]), "");
static_assert(doAssign(spans[1], spans[6]), "");
static_assert(doAssign(spans[1], spans[7]), "");
static_assert(doAssign(spans[1], spans[8]), "");
static_assert(doAssign(spans[1], spans[9]), "");
static_assert(doAssign(spans[1], spans[10]), "");
static_assert(doAssign(spans[1], spans[11]), "");
static_assert(doAssign(spans[1], spans[12]), "");
static_assert(doAssign(spans[2], spans[2]), "");
static_assert(doAssign(spans[2], spans[3]), "");
static_assert(doAssign(spans[2], spans[4]), "");
static_assert(doAssign(spans[2], spans[5]), "");
static_assert(doAssign(spans[2], spans[6]), "");
static_assert(doAssign(spans[2], spans[7]), "");
static_assert(doAssign(spans[2], spans[8]), "");
static_assert(doAssign(spans[2], spans[9]), "");
static_assert(doAssign(spans[2], spans[10]), "");
static_assert(doAssign(spans[2], spans[11]), "");
static_assert(doAssign(spans[2], spans[12]), "");
static_assert(doAssign(spans[3], spans[3]), "");
static_assert(doAssign(spans[3], spans[4]), "");
static_assert(doAssign(spans[3], spans[4]), "");
static_assert(doAssign(spans[3], spans[4]), "");
static_assert(doAssign(spans[3], spans[4]), "");
static_assert(doAssign(spans[3], spans[4]), "");
static_assert(doAssign(spans[3], spans[4]), "");
static_assert(doAssign(spans[3], spans[4]), "");
static_assert(doAssign(spans[3], spans[4]), "");
static_assert(doAssign(spans[3], spans[10]), "");
static_assert(doAssign(spans[3], spans[11]), "");
static_assert(doAssign(spans[3], spans[12]), "");
static_assert(doAssign(spans[4], spans[4]), "");
static_assert(doAssign(spans[4], spans[5]), "");
static_assert(doAssign(spans[4], spans[6]), "");
static_assert(doAssign(spans[4], spans[7]), "");
static_assert(doAssign(spans[4], spans[8]), "");
static_assert(doAssign(spans[4], spans[9]), "");
static_assert(doAssign(spans[4], spans[10]), "");
static_assert(doAssign(spans[4], spans[11]), "");
static_assert(doAssign(spans[4], spans[12]), "");
static_assert(doAssign(spans[5], spans[5]), "");
static_assert(doAssign(spans[5], spans[6]), "");
static_assert(doAssign(spans[5], spans[7]), "");
static_assert(doAssign(spans[5], spans[8]), "");
static_assert(doAssign(spans[5], spans[9]), "");
static_assert(doAssign(spans[5], spans[10]), "");
static_assert(doAssign(spans[5], spans[11]), "");
static_assert(doAssign(spans[5], spans[12]), "");
static_assert(doAssign(spans[6], spans[6]), "");
static_assert(doAssign(spans[6], spans[7]), "");
static_assert(doAssign(spans[6], spans[8]), "");
static_assert(doAssign(spans[6], spans[9]), "");
static_assert(doAssign(spans[6], spans[10]), "");
static_assert(doAssign(spans[6], spans[11]), "");
static_assert(doAssign(spans[6], spans[12]), "");
static_assert(doAssign(spans[7], spans[7]), "");
static_assert(doAssign(spans[7], spans[8]), "");
static_assert(doAssign(spans[7], spans[9]), "");
static_assert(doAssign(spans[7], spans[10]), "");
static_assert(doAssign(spans[7], spans[11]), "");
static_assert(doAssign(spans[7], spans[12]), "");
static_assert(doAssign(spans[8], spans[8]), "");
static_assert(doAssign(spans[8], spans[9]), "");
static_assert(doAssign(spans[8], spans[10]), "");
static_assert(doAssign(spans[8], spans[11]), "");
static_assert(doAssign(spans[8], spans[12]), "");
static_assert(doAssign(spans[9], spans[9]), "");
static_assert(doAssign(spans[9], spans[10]), "");
static_assert(doAssign(spans[9], spans[11]), "");
static_assert(doAssign(spans[9], spans[12]), "");
static_assert(doAssign(spans[10], spans[10]), "");
static_assert(doAssign(spans[10], spans[11]), "");
static_assert(doAssign(spans[10], spans[12]), "");
static_assert(doAssign(spans[11], spans[11]), "");
static_assert(doAssign(spans[11], spans[12]), "");
static_assert(doAssign(spans[12], spans[12]), "");
// for (size_t i = 0; i < std::size(spans); ++i)
// for (size_t j = i; j < std::size(spans); ++j)
// static_assert(doAssign(spans[i], spans[j]), "");
}
// constexpr statically sized assignment
{
using spanType = std::span<const int,2>;
constexpr spanType spans[] = {
spanType{carr1, 2},
spanType{carr1 + 1, 2},
spanType{carr1 + 2, 2},
spanType{carr2, 2},
spanType{carr2 + 1, 2},
spanType{carr3, 2}
};
static_assert(std::size(spans) == 6, "" );
// No for loops in constexpr land :-(
static_assert(doAssign(spans[0], spans[0]), "");
static_assert(doAssign(spans[0], spans[1]), "");
static_assert(doAssign(spans[0], spans[2]), "");
static_assert(doAssign(spans[0], spans[3]), "");
static_assert(doAssign(spans[0], spans[4]), "");
static_assert(doAssign(spans[0], spans[5]), "");
static_assert(doAssign(spans[1], spans[1]), "");
static_assert(doAssign(spans[1], spans[2]), "");
static_assert(doAssign(spans[1], spans[3]), "");
static_assert(doAssign(spans[1], spans[4]), "");
static_assert(doAssign(spans[1], spans[5]), "");
static_assert(doAssign(spans[2], spans[2]), "");
static_assert(doAssign(spans[2], spans[3]), "");
static_assert(doAssign(spans[2], spans[4]), "");
static_assert(doAssign(spans[2], spans[5]), "");
static_assert(doAssign(spans[3], spans[3]), "");
static_assert(doAssign(spans[3], spans[4]), "");
static_assert(doAssign(spans[3], spans[5]), "");
static_assert(doAssign(spans[4], spans[4]), "");
static_assert(doAssign(spans[4], spans[5]), "");
static_assert(doAssign(spans[5], spans[5]), "");
// for (size_t i = 0; i < std::size(spans); ++i)
// for (size_t j = i; j < std::size(spans); ++j)
// static_assert(doAssign(spans[i], spans[j]), "");
}
// dynamically sized assignment
{
std::span<int> spans[] = {
{},
{arr, arr + 1},
{arr, arr + 2},
{arr, arr + 3},
{arr + 1, arr + 3} // same size as s2
};
for (std::size_t i = 0; i < std::size(spans); ++i)
for (std::size_t j = i; j < std::size(spans); ++j)
assert((doAssign(spans[i], spans[j])));
}
// statically sized assignment
{
using spanType = std::span<int,2>;
spanType spans[] = {
spanType{arr, arr + 2},
spanType{arr + 1, arr + 3},
spanType{arr + 2, arr + 4}
};
for (std::size_t i = 0; i < std::size(spans); ++i)
for (std::size_t j = i; j < std::size(spans); ++j)
assert((doAssign(spans[i], spans[j])));
}
// dynamically sized assignment
{
std::span<std::string> spans[] = {
{strs, strs},
{strs, strs + 1},
{strs, strs + 2},
{strs, strs + 3},
{strs + 1, strs + 1},
{strs + 1, strs + 2},
{strs + 1, strs + 3},
{strs + 2, strs + 2},
{strs + 2, strs + 3},
{strs + 3, strs + 3}
};
for (std::size_t i = 0; i < std::size(spans); ++i)
for (std::size_t j = i; j < std::size(spans); ++j)
assert((doAssign(spans[i], spans[j])));
}
{
using spanType = std::span<std::string, 1>;
spanType spans[] = {
spanType{strs, strs + 1},
spanType{strs + 1, strs + 2},
spanType{strs + 2, strs + 3}
};
for (std::size_t i = 0; i < std::size(spans); ++i)
for (std::size_t j = i; j < std::size(spans); ++j)
assert((doAssign(spans[i], spans[j])));
}
return 0;
}
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