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//===----------------------------------------------------------------------===//
//
// 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
// type_traits
// is_nothrow_callable
#include <type_traits>
#include <functional>
#include "test_macros.h"
struct Tag {};
struct Implicit {
Implicit(int) noexcept {}
};
struct ThrowsImplicit {
ThrowsImplicit(int) {}
};
struct Explicit {
explicit Explicit(int) noexcept {}
};
template <bool IsNoexcept, class Ret, class ...Args>
struct CallObject {
Ret operator()(Args&&...) const noexcept(IsNoexcept);
};
template <class Fn>
constexpr bool throws_callable() {
return std::is_callable<Fn>::value &&
!std::is_nothrow_callable<Fn>::value;
}
template <class Fn, class Ret>
constexpr bool throws_callable() {
return std::is_callable<Fn, Ret>::value &&
!std::is_nothrow_callable<Fn, Ret>::value;
}
// FIXME(EricWF) Don't test the where noexcept is *not* part of the type system
// once implementations have caught up.
void test_noexcept_function_pointers()
{
struct Dummy { void foo() noexcept; static void bar() noexcept; };
#if !defined(__cpp_noexcept_function_type)
{
// Check that PMF's and function pointers *work*. is_nothrow_callable will always
// return false because 'noexcept' is not part of the function type.
static_assert(throws_callable<decltype(&Dummy::foo)(Dummy&)>());
static_assert(throws_callable<decltype(&Dummy::bar)()>());
}
#else
{
// Check that PMF's and function pointers actually work and that
// is_nothrow_callable returns true for noexcept PMF's and function
// pointers.
static_assert(std::is_nothrow_callable<decltype(&Dummy::foo)(Dummy&)>::value);
static_assert(std::is_nothrow_callable<decltype(&Dummy::bar)()>::value);
}
#endif
}
int main()
{
{
// Check that the conversion to the return type is properly checked
using Fn = CallObject<true, int>;
static_assert(std::is_nothrow_callable<Fn(), Implicit>::value);
static_assert(std::is_nothrow_callable<Fn(), double>::value);
static_assert(std::is_nothrow_callable<Fn(), const volatile void>::value);
static_assert(throws_callable<Fn(), ThrowsImplicit>());
static_assert(!std::is_nothrow_callable<Fn(), Explicit>());
}
{
// Check that the conversion to the parameters is properly checked
using Fn = CallObject<true, void, const Implicit&, const ThrowsImplicit&>;
static_assert(std::is_nothrow_callable<Fn(Implicit&, ThrowsImplicit&)>::value);
static_assert(std::is_nothrow_callable<Fn(int, ThrowsImplicit&)>::value);
static_assert(throws_callable<Fn(int, int)>());
static_assert(!std::is_nothrow_callable<Fn()>::value);
}
{
// Check that the noexcept-ness of function objects is checked.
using Fn = CallObject<true, void>;
using Fn2 = CallObject<false, void>;
static_assert(std::is_nothrow_callable<Fn()>::value);
static_assert(throws_callable<Fn2()>());
}
{
// Check that PMD derefs are noexcept
using Fn = int (Tag::*);
static_assert(std::is_nothrow_callable<Fn(Tag&)>::value);
static_assert(std::is_nothrow_callable<Fn(Tag&), Implicit>::value);
static_assert(throws_callable<Fn(Tag&), ThrowsImplicit>());
}
{
// Check for is_nothrow_callable_v
using Fn = CallObject<true, int>;
static_assert(std::is_nothrow_callable_v<Fn()>);
static_assert(!std::is_nothrow_callable_v<Fn(int)>);
}
test_noexcept_function_pointers();
}
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