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libcxx/test/std/containers/views/span.cons/stdarray.pass.cpp

115 lines
3.5 KiB
C++

// -*- C++ -*-
//===------------------------------ span ---------------------------------===//
//
// 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.
//
//===---------------------------------------------------------------------===//
// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
// <span>
// template<size_t N>
// constexpr span(array<value_type, N>& arr) noexcept;
// template<size_t N>
// constexpr span(const array<value_type, N>& arr) 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 <span>
#include <cassert>
#include <string>
#include "test_macros.h"
// std::array is explicitly allowed to be initialized with A a = { init-list };.
// Disable the missing braces warning for this reason.
#include "disable_missing_braces_warning.h"
void checkCV()
{
std::array<int, 3> arr = {1,2,3};
// STL says these are not cromulent
// std::array<const int,3> carr = {4,5,6};
// std::array<volatile int, 3> varr = {7,8,9};
// std::array<const volatile int, 3> cvarr = {1,3,5};
// Types the same (dynamic sized)
{
std::span< int> s1{ arr}; // a span< int> pointing at int.
}
// Types the same (static sized)
{
std::span< int,3> s1{ arr}; // a span< int> pointing at int.
}
// 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.
}
// 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.
}
}
template <typename T>
constexpr bool testConstexprSpan()
{
constexpr std::array<T,2> val = { T(), T() };
ASSERT_NOEXCEPT(std::span<const T> {val});
ASSERT_NOEXCEPT(std::span<const T, 2>{val});
std::span<const T> s1{val};
std::span<const T, 2> s2{val};
return
s1.data() == &val[0] && s1.size() == 2
&& s2.data() == &val[0] && s2.size() == 2;
}
template <typename T>
void testRuntimeSpan()
{
std::array<T,2> val;
ASSERT_NOEXCEPT(std::span<T> {val});
ASSERT_NOEXCEPT(std::span<T, 2>{val});
std::span<T> s1{val};
std::span<T, 2> s2{val};
assert(s1.data() == &val[0] && s1.size() == 2);
assert(s2.data() == &val[0] && s2.size() == 2);
}
struct A{};
int main ()
{
static_assert(testConstexprSpan<int>(), "");
static_assert(testConstexprSpan<long>(), "");
static_assert(testConstexprSpan<double>(), "");
static_assert(testConstexprSpan<A>(), "");
testRuntimeSpan<int>();
testRuntimeSpan<long>();
testRuntimeSpan<double>();
testRuntimeSpan<std::string>();
testRuntimeSpan<A>();
checkCV();
}