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/C++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) |
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) |
what_arg as explanatory string. After construction, std::strcmp(what(), what_arg.c_str()) == 0.what_arg as explanatory string. After construction, std::strcmp(what(), what_arg) == 0.*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.
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.
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
|
[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
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https://en.cppreference.com/w/cpp/utility/format/format_error