std::function::operator()
From cppreference.com
< cpp | utility | functional | function
| R operator()( ArgTypes... args ) const; |
(since C++11) | |
Calls the stored callable object with the parameters args.
Contents |
[edit] Parameters
| args | - | parameters to pass to the stored callable object |
[edit] Return value
None if R is void. Otherwise the return value of the invocation of the stored callable object.
[edit] Exceptions
- std::bad_function_call if the stored callable object is not valid, that is, !*this == true.
[edit] Example
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
[edit] See also
| This section is incomplete |
