table of contents
std::format_error(3) | C++ Standard Libary | std::format_error(3) |
NAME¶
std::format_error - std::format_error
Synopsis¶
Defined in header <format>
class format_error; (since C++20)
Defines the type of exception object thrown to report errors in the
formatting
library.
std-format error-inheritance.svg
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)
std::format_error::format_error
format_error( const std::string& what_arg ); (1)
format_error( const char* what_arg ); (2)
format_error( const format_error& other ) noexcept; (3)
1) Constructs the exception object with what_arg as explanatory string. After
construction, std::strcmp(what(), what_arg.c_str()) == 0.
2) Constructs the exception object with what_arg as explanatory string. After
construction, std::strcmp(what(), what_arg) == 0.
3) Copy constructor. If *this and other both have dynamic type
std::format_error
then std::strcmp(what(), other.what()) == 0. No exception can be thrown from
the
copy constructor.
Parameters¶
what_arg - explanatory string
other - another exception object to copy
Exceptions¶
1,2) May throw 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.
A derived standard exception class must have a publicly accessible copy
constructor.
It can be implicitly defined as long as the explanatory strings obtained by
what()
are the same for the original object and the copied object.
std::format_error::operator=
format_error& operator=( const format_error& other ) noexcept;
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. No
exception can be thrown from the copy assignment operator.
Parameters¶
other - another exception object to assign with
Return value¶
*this
Notes¶
A derived standard exception class must have a publicly
accessible copy assignment
operator. It can be implicitly defined as long as the explanatory strings
obtained
by what() are the same for the original object and the copied object.
Inherited from std::runtime_error
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¶
This section is incomplete
Reason: no example
See also¶
Category:¶
* Todo no example
2024.06.10 | http://cppreference.com |