#include <iostream> bool func(int a) { std::cout << "func pointer " << a << std::endl; } int main() { bool (*p)(int) = func; p(10); // or (*p)(10) return 0; } 上述为普通函数指针定义的简单例子。上述代码中,定义了一个函数指针p,其接受的输入参数为int类型,返回类型为boo...
Extracted function pointer and calling it with 42: Function called with: 42 这表明我们成功地从std::function中提取了函数指针,并通过它调用了函数。 5. 整理并给出详细的步骤和说明 步骤1:包含必要的头文件(<functional>)。 步骤2:定义一个或多个函数,这些函数将被封装到std::function中。 步骤...
#include <iostream> #include <chrono> #include <functional> auto res = 0; #pragma GCC push_options #pragma GCC optimize ("O0") long test_func(long i) { return i; } #pragma GCC pop_options auto test_lambda = [](int i) { test_func(i); }; auto test_bind = std::bind(test_f...
#include <iostream> int add(int a, int b) { return a + b; } int main() { int (*funcPtr)(int, int) = &add; std::cout << "Result using function pointer: " << funcPtr(3, 4) << std::endl; return 0; } std::function示例: #include <iostream> #include <functional> int...
In less abstruse English, it means thatstd::functioncan contain almost any object that acts like a function pointer in how you call it. 为了简单的表示:以上赋值语句也可以分为两句: usingmyName = std::function<void(int,int)> myName fp = fun; ...
_Test_callable(_Val)) { // null member pointer/function pointer/std::function return; // already empty } using _Impl = _Func_impl_no_alloc<decay_t<_Fx>, _Ret, _Types...>; if constexpr (_Is_large<_Impl>) { // dynamically allocate _Val _Set(_Global_new<_Impl>(_STD forward<...
std::cout << "Using function pointer: " << func_ptr(3, 4) << std::endl; // 使用std::function std::function<int(int, int)> func = add; std::cout << "Using std::function: " << func(3, 4) << std::endl; return 0; ...
typenameadd_pointer<_Ty1>::type, typenameremove_cv<_Ty1>::type>::type>::type type; }; 至此,我们大致上完成了std::function的原理分析了,希望在后续的使用中,我们能够知道std::function在什么情况下可以使用,以及背后完成的事情。 关于C++ std::function技术浅谈,欢迎在评论中和我探讨。觉得文章不错,请点...
std::cout << "bind to a pointer to member function:\n"; Foo foo; auto f3 = std::bind(&Foo::print_sum, &foo, 95, _1); f3(5); std::cout << "bind to a pointer to data member:\n"; auto f4 = std::bind(&Foo::data, _1); ...
(*_Base::_M_get_pointer(__functor))(std::forward<_ArgTypes>(__args)...); } }; template<typename _Functor, typename... _ArgTypes> class _Function_handler<void(_ArgTypes...), _Functor> : public _Function_base::_Base_manager<_Functor> { typedef _Function_base::_Base_manager<_...