functional::bad_function_call in C++ with Examples

Standard C++ contains several built-in exception classes, functional::bad_function_call is one of them. This is an exception thrown on bad call. Below is the syntax for the same:

Header File:

include<functional>

Syntax:

class bad_function_call;

Note: To make use of functional::bad_function_call, one should set up the appropriate try and catch blocks.

Below are the programs to understand the implementation of functional::bad_function_call in a better way:

Program 1 :

// C++ code for functional::bad_function_call
#include <bits/stdc++.h>

using namespace std;

// main method
int main()
{
    function<int()> gfg = nullptr;

    // try block
    try {
        gfg();
    }

    // catch block to handle the errors
    catch (const bad_function_call& geeksforgeeks) {
        cout << geeksforgeeks.what() << endl;
    }
    return 0;
}

Output:

bad_function_call

Example 2 :

// C++ code for functional::bad_function_call
#include <bits/stdc++.h>

using namespace std;

// main method
int main()
{
    function<int()> geeksforgeeks = nullptr;

    // try block
    try {
        geeksforgeeks();
    }

    // catch block to handle the errors
    catch (const bad_function_call& gfg) {
        cout << gfg.what() << endl;
    }
    return 0;
}

Output:

bad_function_call

Reference: http://www.cplusplus.com/reference/functional/bad_function_call/