//===----------------------------------------------------------------------===//
//
// 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
// <functional>
// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_CXX20_REMOVED_TYPE_TRAITS
// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
// template<class F, class... Args>
// constexpr // constexpr in C++20
// invoke_result_t<F, Args...> invoke(F&& f, Args&&... args)
// noexcept(is_nothrow_invocable_v<_Fn, _Args...>);
/// C++14 [func.def] 20.9.0
/// (1) The following definitions apply to this Clause:
/// (2) A call signature is the name of a return type followed by a parenthesized
/// comma-separated list of zero or more argument types.
/// (3) A callable type is a function object type (20.9) or a pointer to member.
/// (4) A callable object is an object of a callable type.
/// (5) A call wrapper type is a type that holds a callable object and supports
/// a call operation that forwards to that object.
/// (6) A call wrapper is an object of a call wrapper type.
/// (7) A target object is the callable object held by a call wrapper.
/// C++14 [func.require] 20.9.1
///
/// Define INVOKE (f, t1, t2, ..., tN) as follows:
/// (1.1) - (t1.*f)(t2, ..., tN) when f is a pointer to a member function of a class T and t1 is an object of
/// type T or a reference to an object of type T or a reference to an object of a type derived from T;
/// (1.2) - ((*t1).*f)(t2, ..., tN) when f is a pointer to a member function of a class T and t1 is not one of
/// the types described in the previous item;
/// (1.3) - t1.*f when N == 1 and f is a pointer to member data of a class T and t1 is an object of type T or a
/// reference to an object of type T or a reference to an object of a type derived from T;
/// (1.4) - (*t1).*f when N == 1 and f is a pointer to member data of a class T and t1 is not one of the types
/// described in the previous item;
/// (1.5) - f(t1, t2, ..., tN) in all other cases.
#include <functional>
#include <type_traits>
#include <utility> // for std::move
#include <cassert>
#include "test_macros.h"
struct NonCopyable {
constexpr NonCopyable() {}
private:
NonCopyable(NonCopyable const&) = delete;
NonCopyable& operator=(NonCopyable const&) = delete;
};
struct TestClass {
constexpr explicit TestClass(int x) : data(x) {}
constexpr int& operator()(NonCopyable&&) & { return data; }
constexpr int const& operator()(NonCopyable&&) const & { return data; }
constexpr int&& operator()(NonCopyable&&) && { return std::move(data); }
constexpr int const&& operator()(NonCopyable&&) const && { return std::move(data); }
int data;
private:
TestClass(TestClass const&) = delete;
TestClass& operator=(TestClass const&) = delete;
};
struct DerivedFromTestClass : public TestClass {
constexpr explicit DerivedFromTestClass(int x) : TestClass(x) {}
};
static constexpr int data = 42;
constexpr const int& foo(NonCopyable&&) {
return data;
}
template <class Signature, class Expect, class Functor>
constexpr void test_b12(Functor&& f) {
// Create the callable object.
typedef Signature TestClass::*ClassFunc;
ClassFunc func_ptr = &TestClass::operator();
// Create the dummy arg.
NonCopyable arg;
// Check that the deduced return type of invoke is what is expected.
typedef decltype(
std::invoke(func_ptr, std::forward<Functor>(f), std::move(arg))
) DeducedReturnType;
static_assert((std::is_same<DeducedReturnType, Expect>::value), "");
// Check that result_of_t matches Expect.
typedef typename std::result_of<ClassFunc&&(Functor&&, NonCopyable&&)>::type
ResultOfReturnType;
static_assert((std::is_same<ResultOfReturnType, Expect>::value), "");
// Run invoke and check the return value.
DeducedReturnType ret =
std::invoke(func_ptr, std::forward<Functor>(f), std::move(arg));
assert(ret == 42);
}
template <class Expect, class Functor>
constexpr void test_b34(Functor&& f) {
// Create the callable object.
typedef int TestClass::*ClassFunc;
ClassFunc func_ptr = &TestClass::data;
// Check that the deduced return type of invoke is what is expected.
typedef decltype(
std::invoke(func_ptr, std::forward<Functor>(f))
) DeducedReturnType;
static_assert((std::is_same<DeducedReturnType, Expect>::value), "");
// Check that result_of_t matches Expect.
typedef typename std::result_of<ClassFunc&&(Functor&&)>::type
ResultOfReturnType;
static_assert((std::is_same<ResultOfReturnType, Expect>::value), "");
// Run invoke and check the return value.
DeducedReturnType ret =
std::invoke(func_ptr, std::forward<Functor>(f));
assert(ret == 42);
}
template <class Expect, class Functor>
constexpr void test_b5(Functor&& f) {
NonCopyable arg;
// Check that the deduced return type of invoke is what is expected.
typedef decltype(
std::invoke(std::forward<Functor>(f), std::move(arg))
) DeducedReturnType;
static_assert((std::is_same<DeducedReturnType, Expect>::value), "");
// Check that result_of_t matches Expect.
typedef typename std::result_of<Functor&&(NonCopyable&&)>::type
ResultOfReturnType;
static_assert((std::is_same<ResultOfReturnType, Expect>::value), "");
// Run invoke and check the return value.
DeducedReturnType ret = std::invoke(std::forward<Functor>(f), std::move(arg));
assert(ret == 42);
}
constexpr bool bullet_one_two_tests() {
{
TestClass cl(42);
test_b12<int&(NonCopyable&&) &, int&>(cl);
test_b12<int const&(NonCopyable&&) const &, int const&>(cl);
test_b12<int&&(NonCopyable&&) &&, int&&>(std::move(cl));
test_b12<int const&&(NonCopyable&&) const &&, int const&&>(std::move(cl));
}
{
DerivedFromTestClass cl(42);
test_b12<int&(NonCopyable&&) &, int&>(cl);
test_b12<int const&(NonCopyable&&) const &, int const&>(cl);
test_b12<int&&(NonCopyable&&) &&, int&&>(std::move(cl));
test_b12<int const&&(NonCopyable&&) const &&, int const&&>(std::move(cl));
}
{
TestClass cl_obj(42);
std::reference_wrapper<TestClass> cl(cl_obj);
test_b12<int&(NonCopyable&&) &, int&>(cl);
test_b12<int const&(NonCopyable&&) const &, int const&>(cl);
test_b12<int&(NonCopyable&&) &, int&>(std::move(cl));
test_b12<int const&(NonCopyable&&) const &, int const&>(std::move(cl));
}
{
DerivedFromTestClass cl_obj(42);
std::reference_wrapper<DerivedFromTestClass> cl(cl_obj);
test_b12<int&(NonCopyable&&) &, int&>(cl);
test_b12<int const&(NonCopyable&&) const &, int const&>(cl);
test_b12<int&(NonCopyable&&) &, int&>(std::move(cl));
test_b12<int const&(NonCopyable&&) const &, int const&>(std::move(cl));
}
{
TestClass cl_obj(42);
TestClass *cl = &cl_obj;
test_b12<int&(NonCopyable&&) &, int&>(cl);
test_b12<int const&(NonCopyable&&) const &, int const&>(cl);
}
{
DerivedFromTestClass cl_obj(42);
DerivedFromTestClass *cl = &cl_obj;
test_b12<int&(NonCopyable&&) &, int&>(cl);
test_b12<int const&(NonCopyable&&) const &, int const&>(cl);
}
return true;
}
constexpr bool bullet_three_four_tests() {
{
typedef TestClass Fn;
Fn cl(42);
test_b34<int&>(cl);
test_b34<int const&>(static_cast<Fn const&>(cl));
test_b34<int&&>(static_cast<Fn &&>(cl));
test_b34<int const&&>(static_cast<Fn const&&>(cl));
}
{
typedef DerivedFromTestClass Fn;
Fn cl(42);
test_b34<int&>(cl);
test_b34<int const&>(static_cast<Fn const&>(cl));
test_b34<int&&>(static_cast<Fn &&>(cl));
test_b34<int const&&>(static_cast<Fn const&&>(cl));
}
{
typedef TestClass Fn;
Fn cl(42);
test_b34<int&>(std::reference_wrapper<Fn>(cl));
test_b34<int const&>(std::reference_wrapper<Fn const>(cl));
}
{
typedef DerivedFromTestClass Fn;
Fn cl(42);
test_b34<int&>(std::reference_wrapper<Fn>(cl));
test_b34<int const&>(std::reference_wrapper<Fn const>(cl));
}
{
typedef TestClass Fn;
Fn cl_obj(42);
Fn* cl = &cl_obj;
test_b34<int&>(cl);
test_b34<int const&>(static_cast<Fn const*>(cl));
}
{
typedef DerivedFromTestClass Fn;
Fn cl_obj(42);
Fn* cl = &cl_obj;
test_b34<int&>(cl);
test_b34<int const&>(static_cast<Fn const*>(cl));
}
return true;
}
constexpr bool bullet_five_tests() {
using FooType = const int&(NonCopyable&&);
{
FooType& fn = foo;
test_b5<const int &>(fn);
}
{
FooType* fn = foo;
test_b5<const int &>(fn);
}
{
typedef TestClass Fn;
Fn cl(42);
test_b5<int&>(cl);
test_b5<int const&>(static_cast<Fn const&>(cl));
test_b5<int&&>(static_cast<Fn &&>(cl));
test_b5<int const&&>(static_cast<Fn const&&>(cl));
}
return true;
}
int main(int, char**) {
bullet_one_two_tests();
bullet_three_four_tests();
bullet_five_tests();
static_assert(bullet_one_two_tests());
static_assert(bullet_three_four_tests());
static_assert(bullet_five_tests());
return 0;
}
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