std::function::operator()
来自cppreference.com
< cpp | utility | functional | function
 |
This page has been machine-translated from the English version of the wiki using Google Translate.
The translation may contain errors and awkward wording. Hover over text to see the original version. You can help to fix errors and improve the translation. For instructions click here. |
| R operator()( ArgTypes... args ) const; |
（C++11 起） | |
Calls the stored callable function target with the parameters args.
目錄 |
[编辑] 參數
| args | - | parameters to pass to the stored callable function target |
[编辑] 返回值
None if R is void. Otherwise the return value of the invocation of the stored callable object.
[编辑] 例外
- std::bad_function_call if *this does not store a callable function target, !*this == true.
[编辑] 為例
The following example shows how std::function can passed to other functions by value. Also, it shown how std::function can store lambdas.
#include <iostream> #include <functional> void call(std::function<int()> f) // can be passed by value { std::cout << f() << '\n'; } int normal_function() { return 42; } int main() { int n = 1; std::function<int()> f = [&n](){ return n; }; call(f); n = 2; call(f); f = normal_function; call(f); }
Output:
1 2 42
[编辑] 另請參閱
| 本節是不完整的 |
