# std::function<R(Args...)>::target

From cppreference.com
< cpp‎ | utility‎ | functional‎ | function

template< class T > T* target() noexcept; | (1) | (since C++11)
template< class T > const T* target() const noexcept; | (2) | (since C++11)

Returns a pointer to the stored callable function target.

### Parameters

(none)

### Return value

A pointer to the stored function if target_type() == typeid(T), otherwise a null pointer.

### Example

Run this code

    #include <functional>
    #include <iostream>

    int f(int, int) { return 1; }
    int g(int, int) { return 2; }
    void test(std::function<int(int, int)> const& arg)
    {
        std::cout << "test function: ";
        if (arg.target<std::plus<int>>())
            std::cout << "it is plus\n";
        if (arg.target<std::minus<int>>())
            std::cout << "it is minus\n";

        int (*const* ptr)(int, int) = arg.target<int(*)(int, int)>();
        if (ptr && *ptr == f)
            std::cout << "it is the function f\n";
        if (ptr && *ptr == g)
            std::cout << "it is the function g\n";
    }

    int main()
    {
        test(std::function<int(int, int)>(std::plus<int>()));
        test(std::function<int(int, int)>(std::minus<int>()));
        test(std::function<int(int, int)>(f));
        test(std::function<int(int, int)>(g));
    }

Output:

    test function: it is plus
    test function: it is minus
    test function: it is the function f
    test function: it is the function g

### Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR | Applied to | Behavior as published | Correct behavior
--- | --- | --- | ---
LWG 2591 | C++11 | the behavior is undefined if `T` is not Callable | behavior is defined (always returns `nullptr`)

### See also

target_type | obtains the typeid of the stored target (public member function)

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