std::bad_function_call
<functional>
std::bad_function_call is the type of the exception thrown by std::function::operator() if the function wrapper has no target.
Inheritance diagram
Contents
[edit] Member functions
bad_function_call object (public member function)
bad_function_call object (public member function)
(public member function)
std::bad_function_call::bad_function_call
Constructs a new bad_function_call object with an implementation-defined null-terminated byte string which is accessible through what().
std::bad_function_call then std::strcmp (what(), other.what()) == 0.Parameters
std::bad_function_call::operator=
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
Return value
*this
std::bad_function_call::what
Returns the explanatory string.
Return value
Pointer to an implementation-defined 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
[edit] Example
#include <functional> #include <iostream> 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] 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 2233 | C++11 | what() always returned the same explanatorystring as std::exception::what() |
returns its own explanatory string |