//===----------------------------------------------------------------------===//
//
// 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 N>
// constexpr span(element_type (&arr)[N]) noexcept;
//
// Remarks: These constructors shall not participate in overload resolution unless:
// - extent == dynamic_extent || N == extent is true, and
// - remove_pointer_t<decltype(data(arr))>(*)[] is convertible to ElementType(*)[].
//
#include <cassert>
#include <span>
#include <string>
#include <type_traits>
#include "test_macros.h"
void checkCV()
{
int arr[] = {1,2,3};
const int carr[] = {4,5,6};
volatile int varr[] = {7,8,9};
const volatile int cvarr[] = {1,3,5};
// Types the same (dynamic sized)
{
std::span< int> s1{ arr}; // a span< int> pointing at int.
std::span<const int> s2{ carr}; // a span<const int> pointing at const int.
std::span< volatile int> s3{ varr}; // a span< volatile int> pointing at volatile int.
std::span<const volatile int> s4{cvarr}; // a span<const volatile int> pointing at const volatile int.
assert(s1.size() + s2.size() + s3.size() + s4.size() == 12);
}
// Types the same (static sized)
{
std::span< int,3> s1{ arr}; // a span< int> pointing at int.
std::span<const int,3> s2{ carr}; // a span<const int> pointing at const int.
std::span< volatile int,3> s3{ varr}; // a span< volatile int> pointing at volatile int.
std::span<const volatile int,3> s4{cvarr}; // a span<const volatile int> pointing at const volatile int.
assert(s1.size() + s2.size() + s3.size() + s4.size() == 12);
}
// types different (dynamic sized)
{
std::span<const int> s1{ arr}; // a span<const int> pointing at int.
std::span< volatile int> s2{ arr}; // a span< volatile int> pointing at int.
std::span< volatile int> s3{ arr}; // a span< volatile int> pointing at const int.
std::span<const volatile int> s4{ arr}; // a span<const volatile int> pointing at int.
std::span<const volatile int> s5{carr}; // a span<const volatile int> pointing at const int.
std::span<const volatile int> s6{varr}; // a span<const volatile int> pointing at volatile int.
assert(s1.size() + s2.size() + s3.size() + s4.size() + s5.size() + s6.size() == 18);
}
// types different (static sized)
{
std::span<const int,3> s1{ arr}; // a span<const int> pointing at int.
std::span< volatile int,3> s2{ arr}; // a span< volatile int> pointing at int.
std::span< volatile int,3> s3{ arr}; // a span< volatile int> pointing at const int.
std::span<const volatile int,3> s4{ arr}; // a span<const volatile int> pointing at int.
std::span<const volatile int,3> s5{carr}; // a span<const volatile int> pointing at const int.
std::span<const volatile int,3> s6{varr}; // a span<const volatile int> pointing at volatile int.
assert(s1.size() + s2.size() + s3.size() + s4.size() + s5.size() + s6.size() == 18);
}
}
template<class T>
constexpr bool testSpan()
{
T val[2] = {};
ASSERT_NOEXCEPT(std::span<T>{val});
ASSERT_NOEXCEPT(std::span<T, 2>{val});
ASSERT_NOEXCEPT(std::span<const T>{val});
ASSERT_NOEXCEPT(std::span<const T, 2>{val});
std::span<T> s1 = val;
std::span<T, 2> s2 = val;
std::span<const T> s3 = val;
std::span<const T, 2> s4 = val;
assert(s1.data() == val && s1.size() == 2);
assert(s2.data() == val && s2.size() == 2);
assert(s3.data() == val && s3.size() == 2);
assert(s4.data() == val && s4.size() == 2);
std::span<const int> s5 = {{1,2}};
#if TEST_STD_VER >= 26
std::span<const int, 2> s6({1, 2});
#else
std::span<const int, 2> s6 = {{1,2}};
#endif
assert(s5.size() == 2); // and it dangles
assert(s6.size() == 2); // and it dangles
return true;
}
struct A {};
int main(int, char**)
{
testSpan<int>();
testSpan<double>();
testSpan<A>();
testSpan<std::string>();
static_assert(testSpan<int>());
static_assert(testSpan<double>());
static_assert(testSpan<A>());
checkCV();
// Size wrong
{
static_assert(!std::is_constructible<std::span<int, 2>, int (&)[3]>::value, "");
}
// Type wrong
{
static_assert(!std::is_constructible<std::span<float>, int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<float, 3>, int (&)[3]>::value, "");
}
// CV wrong (dynamically sized)
{
static_assert(!std::is_constructible<std::span<int>, const int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<int>, volatile int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<int>, const volatile int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<const int>, volatile int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<const int>, const volatile int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<volatile int>, const int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<volatile int>, const volatile int (&)[3]>::value, "");
}
// CV wrong (statically sized)
{
static_assert(!std::is_constructible<std::span<int, 3>, const int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<int, 3>, volatile int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<int, 3>, const volatile int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<const int, 3>, volatile int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<const int, 3>, const volatile int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<volatile int, 3>, const int (&)[3]>::value, "");
static_assert(!std::is_constructible<std::span<volatile int, 3>, const volatile int (&)[3]>::value, "");
}
return 0;
}
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