std::reference_wrapper::operator()
From cppreference.com
< cpp | utility | functional | reference wrapper
| template< class... ArgTypes > typename std::result_of<T&(ArgTypes&&...)>::type |
(since C++11) (until C++17) |
|
| template< class... ArgTypes > std::invoke_result_t<T&, ArgTypes...> |
(since C++17) | |
Calls the Callable object, reference to which is stored. This function is available only if the stored reference points to a Callable object.
Parameters
| args | - | arguments to pass to the called function |
Return value
The return value of the called function.
Exceptions
(none)
Example
Run this code
#include <iostream> #include <functional> void f1() { std::cout << "reference to function called\n"; } void f2(int n) { std::cout << "bind expression called with " << n << " as the argument\n"; } int main() { std::reference_wrapper<void()> ref1 = std::ref(f1); ref1(); auto b = std::bind(f2, std::placeholders::_1); auto ref2 = std::ref(b); ref2(7); auto c = []{std::cout << "lambda function called\n"; }; auto ref3 = std::ref(c); ref3(); }
Output:
reference to function called bind expression called with 7 as the argument lambda function called
See also
| accesses the stored reference (public member function) |