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std::bad_function_call

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< cpp‎ | utility‎ | functional
 
 
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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.

cpp/error/exceptionstd-bad function call-inheritance.svg

Inheritance diagram

Contents

[edit] 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 ) noexcept;
(since C++11)

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

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

[edit] Example

#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

[edit] See also

(C++11)
wraps callable object of any type with specified function call signature
(class template) [edit]