//===----------------------------------------------------------------------===//
//
// 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
// <functional>
// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_CXX20_REMOVED_TYPE_TRAITS
// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
// template<class F, class... Args>
// invoke_result_t<F, Args...> invoke(F&& f, Args&&... args) // C++17
// 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 {
NonCopyable() {}
private:
NonCopyable(NonCopyable const&) = delete;
NonCopyable& operator=(NonCopyable const&) = delete;
};
struct TestClass {
explicit TestClass(int x) : data(x) {}
int& operator()(NonCopyable&&) & { return data; }
int const& operator()(NonCopyable&&) const & { return data; }
int volatile& operator()(NonCopyable&&) volatile & { return data; }
int const volatile& operator()(NonCopyable&&) const volatile & { return data; }
int&& operator()(NonCopyable&&) && { return std::move(data); }
int const&& operator()(NonCopyable&&) const && { return std::move(data); }
int volatile&& operator()(NonCopyable&&) volatile && { return std::move(data); }
int const volatile&& operator()(NonCopyable&&) const volatile && { return std::move(data); }
int data;
private:
TestClass(TestClass const&) = delete;
TestClass& operator=(TestClass const&) = delete;
};
struct DerivedFromTestClass : public TestClass {
explicit DerivedFromTestClass(int x) : TestClass(x) {}
};
int& foo(NonCopyable&&) {
static int data = 42;
return data;
}
template <class Signature, class Expect, class Functor>
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>
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>
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);
}
void 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 volatile&(NonCopyable&&) volatile &, int volatile&>(cl);
test_b12<int const volatile&(NonCopyable&&) const volatile &, int const volatile&>(cl);
test_b12<int&&(NonCopyable&&) &&, int&&>(std::move(cl));
test_b12<int const&&(NonCopyable&&) const &&, int const&&>(std::move(cl));
test_b12<int volatile&&(NonCopyable&&) volatile &&, int volatile&&>(std::move(cl));
test_b12<int const volatile&&(NonCopyable&&) const volatile &&, int const volatile&&>(std::move(cl));
}
{
DerivedFromTestClass cl(42);
test_b12<int&(NonCopyable&&) &, int&>(cl);
test_b12<int const&(NonCopyable&&) const &, int const&>(cl);
test_b12<int volatile&(NonCopyable&&) volatile &, int volatile&>(cl);
test_b12<int const volatile&(NonCopyable&&) const volatile &, int const volatile&>(cl);
test_b12<int&&(NonCopyable&&) &&, int&&>(std::move(cl));
test_b12<int const&&(NonCopyable&&) const &&, int const&&>(std::move(cl));
test_b12<int volatile&&(NonCopyable&&) volatile &&, int volatile&&>(std::move(cl));
test_b12<int const volatile&&(NonCopyable&&) const volatile &&, int const volatile&&>(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 volatile&(NonCopyable&&) volatile &, int volatile&>(cl);
test_b12<int const volatile&(NonCopyable&&) const volatile &, int const volatile&>(cl);
test_b12<int&(NonCopyable&&) &, int&>(std::move(cl));
test_b12<int const&(NonCopyable&&) const &, int const&>(std::move(cl));
test_b12<int volatile&(NonCopyable&&) volatile &, int volatile&>(std::move(cl));
test_b12<int const volatile&(NonCopyable&&) const volatile &, int const volatile&>(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 volatile&(NonCopyable&&) volatile &, int volatile&>(cl);
test_b12<int const volatile&(NonCopyable&&) const volatile &, int const volatile&>(cl);
test_b12<int&(NonCopyable&&) &, int&>(std::move(cl));
test_b12<int const&(NonCopyable&&) const &, int const&>(std::move(cl));
test_b12<int volatile&(NonCopyable&&) volatile &, int volatile&>(std::move(cl));
test_b12<int const volatile&(NonCopyable&&) const volatile &, int const volatile&>(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);
test_b12<int volatile&(NonCopyable&&) volatile &, int volatile&>(cl);
test_b12<int const volatile&(NonCopyable&&) const volatile &, int const volatile&>(cl);
}
{
DerivedFromTestClass cl_obj(42);
DerivedFromTestClass *cl = &cl_obj;
test_b12<int&(NonCopyable&&) &, int&>(cl);
test_b12<int const&(NonCopyable&&) const &, int const&>(cl);
test_b12<int volatile&(NonCopyable&&) volatile &, int volatile&>(cl);
test_b12<int const volatile&(NonCopyable&&) const volatile &, int const volatile&>(cl);
}
}
void 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 volatile&>(static_cast<Fn volatile&>(cl));
test_b34<int const volatile&>(static_cast<Fn const volatile &>(cl));
test_b34<int&&>(static_cast<Fn &&>(cl));
test_b34<int const&&>(static_cast<Fn const&&>(cl));
test_b34<int volatile&&>(static_cast<Fn volatile&&>(cl));
test_b34<int const volatile&&>(static_cast<Fn const volatile&&>(cl));
}
{
typedef DerivedFromTestClass Fn;
Fn cl(42);
test_b34<int&>(cl);
test_b34<int const&>(static_cast<Fn const&>(cl));
test_b34<int volatile&>(static_cast<Fn volatile&>(cl));
test_b34<int const volatile&>(static_cast<Fn const volatile &>(cl));
test_b34<int&&>(static_cast<Fn &&>(cl));
test_b34<int const&&>(static_cast<Fn const&&>(cl));
test_b34<int volatile&&>(static_cast<Fn volatile&&>(cl));
test_b34<int const volatile&&>(static_cast<Fn const volatile&&>(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));
test_b34<int volatile&>(std::reference_wrapper<Fn volatile>(cl));
test_b34<int const volatile&>(std::reference_wrapper<Fn const volatile>(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));
test_b34<int volatile&>(std::reference_wrapper<Fn volatile>(cl));
test_b34<int const volatile&>(std::reference_wrapper<Fn const volatile>(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));
test_b34<int volatile&>(static_cast<Fn volatile*>(cl));
test_b34<int const volatile&>(static_cast<Fn const volatile *>(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));
test_b34<int volatile&>(static_cast<Fn volatile*>(cl));
test_b34<int const volatile&>(static_cast<Fn const volatile *>(cl));
}
}
void bullet_five_tests() {
using FooType = int&(NonCopyable&&);
{
FooType& fn = foo;
test_b5<int &>(fn);
}
{
FooType* fn = foo;
test_b5<int &>(fn);
}
{
typedef TestClass Fn;
Fn cl(42);
test_b5<int&>(cl);
test_b5<int const&>(static_cast<Fn const&>(cl));
test_b5<int volatile&>(static_cast<Fn volatile&>(cl));
test_b5<int const volatile&>(static_cast<Fn const volatile &>(cl));
test_b5<int&&>(static_cast<Fn &&>(cl));
test_b5<int const&&>(static_cast<Fn const&&>(cl));
test_b5<int volatile&&>(static_cast<Fn volatile&&>(cl));
test_b5<int const volatile&&>(static_cast<Fn const volatile&&>(cl));
}
}
struct CopyThrows {
CopyThrows() {}
CopyThrows(CopyThrows const&) {}
CopyThrows(CopyThrows&&) noexcept {}
};
struct NoThrowCallable {
void operator()() noexcept {}
void operator()(CopyThrows) noexcept {}
};
struct ThrowsCallable {
void operator()() {}
};
struct MemberObj {
int x;
};
void noexcept_test() {
{
NoThrowCallable obj; ((void)obj); // suppress unused warning
CopyThrows arg; ((void)arg); // suppress unused warning
static_assert(noexcept(std::invoke(obj)), "");
static_assert(!noexcept(std::invoke(obj, arg)), "");
static_assert(noexcept(std::invoke(obj, std::move(arg))), "");
}
{
ThrowsCallable obj; ((void)obj); // suppress unused warning
static_assert(!noexcept(std::invoke(obj)), "");
}
{
MemberObj obj{42}; ((void)obj); // suppress unused warning.
static_assert(noexcept(std::invoke(&MemberObj::x, obj)), "");
}
}
// LWG3655: The INVOKE operation and union types
void union_tests() {
union Union {
int x;
int f() { return 42; }
int g() const { return 52; }
};
// With a data member
{
auto get = []() -> Union { return Union{.x = 3}; };
int result = std::invoke(&Union::x, get());
assert(result == 3);
}
{
auto get = []() -> Union const { return Union{.x = 3}; };
int result = std::invoke(&Union::x, get());
assert(result == 3);
}
{
Union u{3};
int& result = std::invoke(&Union::x, u);
assert(&result == &u.x);
}
{
Union const u{3};
int const& result = std::invoke(&Union::x, u);
assert(&result == &u.x);
}
// With a pointer to a member function
{
auto get = []() -> Union { return Union{.x = 3}; };
int result = std::invoke(&Union::f, get());
assert(result == 42);
}
{
Union u{3};
int result = std::invoke(&Union::f, u);
assert(result == 42);
}
{
// constness mismatch
static_assert(!std::is_invocable_v<int (Union::*)(), Union const>);
static_assert(!std::is_invocable_v<int (Union::*)(), Union const&>);
}
{
auto get = []() -> Union { return Union{.x = 3}; };
int result = std::invoke(&Union::g, get());
assert(result == 52);
}
{
auto get = []() -> Union const { return Union{.x = 3}; };
int result = std::invoke(&Union::g, get());
assert(result == 52);
}
{
Union u{3};
int result = std::invoke(&Union::g, u);
assert(result == 52);
}
{
Union const u{3};
int result = std::invoke(&Union::g, u);
assert(result == 52);
}
}
int main(int, char**) {
bullet_one_two_tests();
bullet_three_four_tests();
bullet_five_tests();
noexcept_test();
return 0;
}
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