std::reference_wrapper<T>::operator()
template< class... ArgTypes >
typename std::result_of<T&(ArgTypes&&...)>::type
operator() ( ArgTypes&&... args ) const; |
(since C++11) (until C++17) |
|
template< class... ArgTypes >
std::invoke_result_t<T&, ArgTypes...>
operator() ( ArgTypes&&... args ) const; |
(since C++17) (until C++20) |
|
template< class... ArgTypes >
constexpr std::invoke_result_t<T&, ArgTypes...>
operator() ( ArgTypes&&... args ) const; |
(since C++20) |
Calls the Callable object, reference to which is stored. This function is available only if the stored reference points to a Callable object.
T must be a complete type.
Parameters
| args | - | arguments to pass to the called function |
Return value
The return value of the called function.
Exceptions
May throw implementation-defined exceptions.
Example
#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) |
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