c++的lambda, std::function, function pointer 性能比较? 根本问题: 要使用 #pragma GCC optimize ("O0") 禁止编译器对test_func 这个无关紧要的函数进行优化。 性能测试最重要的是抓住重点。 我修改后测试了一下,lambda最快,bind最慢。原理可以去看汇编。 代码如下: #include <iostream> #include <chrono>...
int lambda_main (int n) { int (*lambda_instance)(int arg); static char_u *who_st...
std::function<void(int)> f = std::bind(&A::Test, a, std::placeholders::_1); std::string name = typeid(function_traits<decltype(f)>::pointer).name();
_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<...
// assign wrapper holding reference_wrapper to function object this->_Tidy; this->_Reset(_Func); return(*this); } 我们看this->_Reset(_Func)这个函数,因为这个才是设置函数可调用对象的东西。 void_Set(_Ptrt *_Ptr) _NOEXCEPT {// store pointer to object ...
Let me just get rid of this and copy a pointer to a heap generated pointer to the std::function object instead. This is fine but it doesn't work. 1234567891011 void some_call(void *arg) { std::function<void()> **g = static_cast<std::function<void()> **>(arg); (**g)(); ...
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); ...
在seminar.cpp中,此处: std::function<std::vector<uint8_t>(Nor::Range &)> Func = &drive; drive是一个成员函数。它需要调用this指针。 您可以通过将其包装在lambda中...
#include<random>#include<iostream>#include<memory>#include<functional>struct Foo{voidprint_sum(int n1,int n2){std::cout<<n1+n2<<'\n';}int data=10;};intmain(){using namespace std::placeholders;// for _1, _2, _3...std::cout<<"1) bind to a pointer to member function: ";Foo...
Class template std::function is a general-purpose polymorphic function wrapper. Instances of std::function can store, copy, and invoke any Callable target -- functions, lambda expressions, bind expressions, or other function objects, as well as pointers to member functions and pointers to data me...