std::bad_function_call - cppreference.com (original) (raw)

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

• 1 Member functions
• 2 std::bad_function_call::bad_function_call
  • 2.1 Parameters
• 3 std::bad_function_call::operator=
  • 3.1 Parameters
  • 3.2 Return value
• 4 std::bad_function_call::what
  • 4.1 Return value
  • 4.2 Notes
• 5 Inherited from std::exception
  • 5.1 Member functions
  • 5.2 Example
  • 5.3 Defect reports
  • 5.4 See also

[edit] Member functions

| | constructs a new bad_function_call object (public member function) | | ----------------------------------------------------------------------- | | | replaces the bad_function_call object (public member function) | | | returns the explanatory string (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().

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

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

Return value

*this

std::bad_function_call::what

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

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

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

[edit] Example

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

Possible output:

[edit] Defect reports

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

[edit] See also

| | copyable wrapper of any copy constructible callable object (class template) [edit] | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |