NAME¶

std::bad_function_call - std::bad_function_call

Synopsis¶

Defined in header <functional>
class bad_function_call; (since C++11)

std::bad_function_call is the type of the exception thrown by
std::function::operator() if the function wrapper has no target.

std-bad function call-inheritance.svg

Inheritance diagram

Member functions¶

constructor constructs a new bad_function_call object
(public member function)
operator= replaces the bad_function_call object
(public member function)
what returns the explanatory string
(public member function)

std::bad_function_call::bad_function_call

bad_function_call() noexcept; (1) (since C++11)
bad_function_call( const bad_function_call& other ) noexcept; (2) (since C++11)

Constructs a new bad_function_call object with an implementation-defined
null-terminated byte string which is accessible through what().

1) Default constructor.
2) Copy constructor. If *this and other both have dynamic type
std::bad_function_call then std::strcmp(what(), other.what()) == 0.

Parameters¶

other - another exception object to copy

std::bad_function_call::operator=

bad_function_call& operator=( const bad_function_call& other ) (since C++11)
noexcept;

Assigns the contents with those of other. If *this and other both have dynamic type
std::bad_function_call then std::strcmp(what(), other.what()) == 0 after assignment.

Parameters¶

other - another exception object to assign with

Return value¶

*this

std::bad_function_call::what

virtual const char* what() const noexcept; (since C++11)

Returns the explanatory string.

Parameters¶

(none)

Return value¶

Pointer to a null-terminated string with explanatory information. The string is
suitable for conversion and display as a std::wstring. The pointer is guaranteed to
be valid at least until the exception object from which it is obtained is destroyed,
or until a non-const member function (e.g. copy assignment operator) on the
exception object is called.

Notes¶

Implementations are allowed but not required to override what().

Inherited from std::exception

Member functions¶

destructor destroys the exception object
[virtual] (virtual public member function of std::exception)
what returns an explanatory string
[virtual] (virtual public member function of std::exception)

Example¶

// Run this code

#include <iostream>
#include <functional>

int main()
{
std::function<int()> f = nullptr;
try {
f();
} catch(const std::bad_function_call& e) {
std::cout << e.what() << '\n';
}
}

Possible output:¶

bad function call

See also¶

function wraps callable object of any copy constructible type with specified
(C++11) function call signature
(class template)