的引用类型使用 result_of。例如: template<class F, class... Args> std::result_of_t<F&&(Args&&...)> // 替代错误的 std::result_of_t<F(Args...)> my_invoke(F&& f, Args&&... args) { /* 实现 */ }注解功能特性测试宏值 标准 功能特性 __cpp_lib_result_of_sfinae 201210L (C++...
(__cpp_lib_invoke_r) auto add = [](int x, int y){ return x + y; }; std::cout << "invoke a lambda converting result to float: "; auto ret = std::invoke_r<float>(add, 11, 22); static_assert(std::is_same<decltype(ret), float>()); std::cout << std::fixed << ret...
std::invoke_result_t<F, Args...> invoke(F&& f, Args&&... args) noexcept(/* see below */); (C++17 起) // 摘自cppreference #include <functional>#include<iostream>structFoo { Foo(intnum) : num_(num) {}voidprint_add(inti)const{ std::cout << num_+i <<'\n'; }intnum_; }...
std::invoke_result_t<F, Args...>invoke(F&&f, Args&&...args)noexcept(/* see below */); (since C++17) Invoke theCallableobjectfwith the parametersargs. As byINVOKE(std::forward<F>(f),std::forward<Args>(args)...). whereINVOKE(f, t1, t2, ..., tN)is defined as follows: ...
constexpr std::invoke_result_t<F, Args...> invoke(F&& f, Args&&... args) noexcept(/* see below */); (C++20 起) 以参数 f 调用可调用 (Callable) 对象。如同以 INVOKE(std::forward<F>(f), std::forward<Args>(args)...)。 其中INVOKE(f, t1, t2, ..., tN) 定义如下: 若...
using invoke_result_t = typename invoke_result<F, ArgTypes...>::type; (2) (C++17 起) 可能的实现 namespace detail { template <class T> struct is_reference_wrapper : std::false_type {}; template <class U> struct is_reference_wrapper<std::reference_wrapper<U>> : std::true_type ...
(0); } template<class T, class U> int f(U u) { std::cout << "overload of f for non-callable T\n"; return u; } int main() { // 以 char 和 int 参数调用 S 的结果是 double std::result_of<S(char, int&)>::type d = 3.14; // d 拥有 double 类型 static_assert(std::...
MSVC\14.27.29110\include\type_traits(1748): note: see reference to alias template instantiation 'std::_Decltype_invoke_nonzero<Functor,Abstract,>' being compiled .\CMakeProject1.cpp(24): note: see reference to alias template instantiation 'std::invoke_result_t<Functor,Abstract>' being ...
_Args> decltype(_Fp{}(0, 0)) __invoke(_Fp&& __f); template<typename T> struct type_identity { using type = T; }; template<class Fn> struct invoke_result : type_identity<decltype(__invoke(Fn{}))> {}; namespace std { struct source_location { struct __impl { const char *_M...
extern "C" void __cdecl _invalid_parameter( wchar_t const* const expression, wchar_t const* const function_name, wchar_t const* const file_name, unsigned int const line_number, uintptr_t const reserved); extern "C" void __cdecl _invalid_parameter_noinfo(void); extern "C" __decl...