std::function<R(Args...)>::swap

From cppreference.com
< cpp‎ | utility‎ | functional‎ | function
C++
Utilities library
General utilities
Relational operators (deprecated in C++20)
Integer comparison functions
(C++20)(C++20)(C++20)
(C++20)
Swap and type operations
(C++20)
(C++14)
(C++11)
(C++23)
(C++11)
(C++23)
(C++11)
(C++11)
(C++17)
Common vocabulary types
(C++11)
(C++17)
(C++17)
(C++17)
(C++11)
(C++11)
(C++17)
(C++17)
(C++23)



Function objects
Function invocation
(C++17)(C++23)
Identity function object
(C++20)
Transparent operator wrappers
(C++14)
(C++14)
(C++14)
(C++14)  
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)

Old binders and adaptors
(until C++17*)
(until C++17*)
(until C++17*)
(until C++17*)
(until C++17*)  
(until C++17*)
(until C++17*) (until C++17*) (until C++17*) (until C++17*)
(until C++20*)
(until C++20*)
(until C++17*)(until C++17*)
(until C++17*)(until C++17*)

(until C++17*)
(until C++17*) (until C++17*) (until C++17*) (until C++17*)
(until C++20*)
(until C++20*)
std::function
void swap( function& other ) noexcept;
 (since C++11)

Exchanges the stored callable objects of *this and other.

Parameters

other - function wrapper to exchange the stored callable object with

Return value

(none)

Example

Run this code
#include <functional>
#include <iostream>
 
void foo(const char* str, int x)
{
    std::cout << "foo(\"" << str << "\", " << x << ")\n";
}
 
void bar(const char* str, int x)
{
    std::cout << "bar(\"" << str << "\", " << x << ")\n";
}
 
int main()
{
    std::function<void(const char*, int)> f1{foo};
    std::function<void(const char*, int)> f2{bar};
 
    f1("f1", 1);
    f2("f2", 2);
 
    std::cout << "f1.swap(f2);\n";
    f1.swap(f2);
 
    f1("f1", 1);
    f2("f2", 2);
}

Output: 

foo("f1", 1)
bar("f2", 2)
f1.swap(f2);
bar("f1", 1)
foo("f2", 2)

See also

 swaps the targets of two std::move_only_function objects
(public member function of std::move_only_function)
Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/utility/functional/function/swap&oldid=176857