std::format_error
Defined in header <format> |
||
|---|---|---|
class format_error; |
(since C++20) |
Defines the type of exception object thrown to report errors in the formatting library.
Inheritance diagram.
Member functions
|
(constructor)
|
constructs a new format_error object with the given message (public member function) |
|
operator=
|
replaces the format_error object (public member function) |
|
what
|
returns the explanatory string (public member function) |
std::format_error::format_error
format_error( const std::string& what_arg ); |
(1) | (since C++20) |
format_error( const char* what_arg ); |
(2) | (since C++20) |
format_error( const format_error& other ) noexcept; |
(3) | (since C++20) |
what_arg as explanatory string that can be accessed through
what().
*this and
other both have dynamic type
std::format_error then
std::strcmp(what(), other.what()) == 0.
Parameters
| what_arg | - | explanatory string |
| other | - | another exception object to copy |
Exceptions
std::bad_alloc
Notes
Because copying std::format_error is not permitted to throw exceptions, this message is typically stored internally as a separately-allocated reference-counted string. This is also why there is no constructor taking std::string&&: it would have to copy the content anyway.
std::format_error::operator=
format_error& operator=( const format_error& other ) noexcept; |
(since C++20) |
Assigns the contents with those of other. If *this and other both have dynamic type std::format_error then std::strcmp(what(), other.what()) == 0 after assignment.
Parameters
| other | - | another exception object to assign with |
Return value
*this.
std::format_error::what
virtual const char* what() const noexcept; |
(since C++20) |
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::runtime_error
Inherited from std::exception
Member functions
|
[virtual]
|
destroys the exception object (virtual public member function of std::exception) |
|
[virtual]
|
returns an explanatory string (virtual public member function of std::exception) |
Example
See also
© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/utility/format/format_error
