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std::domain_error

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Defined in header <stdexcept>
class domain_error;

Defines a type of object to be thrown as exception. It may be used by the implementation to report domain errors, that is, situations where the inputs are outside of the domain on which an operation is defined.

The standard library components do not throw this exception (mathematical functions report domain errors as specified in math_errhandling). Third-party libraries, however, use this. For example, boost.math throws std::domain_error if boost::math::policies::throw_on_error is enabled (the default setting).

cpp/error/exceptioncpp/error/logic errorstd-domain error-inheritance.svg
About this image

Inheritance diagram

Contents

[edit] Member functions

(constructor)
constructs a new domain_error object with the given message
(public member function)
operator=
replaces the domain_error object
(public member function)
what
returns the explanatory string
(public member function)

std::domain_error::domain_error

domain_error( const std::string& what_arg );
(1)
domain_error( const char* what_arg );
(2) (since C++11)
(3)
domain_error( const domain_error& other );
(until C++11)
domain_error( const domain_error& other ) noexcept;
(since C++11)
1-2) Constructs the exception object with what_arg as explanatory string that can be accessed through what().
3) Copy constructor. If *this and other both have dynamic type std::domain_error then std::strcmp(what(), other.what()) == 0. (since C++11)

Parameters

what_arg - explanatory string
other - another exception object to copy

Exceptions

1-2) May throw std::bad_alloc

Notes

Because copying std::domain_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::domain_error::operator=

domain_error& operator=( const domain_error& other );
(until C++11)
domain_error& operator=( const domain_error& other ) noexcept;
(since C++11)

Assigns the contents with those of other. If *this and other both have dynamic type std::domain_error then std::strcmp(what(), other.what()) == 0 after assignment. (since C++11)

Parameters

other - another exception object to assign with

Return value

*this

std::domain_error::what

virtual const char* what() const throw();
(until C++11)
virtual const char* what() const noexcept;
(since C++11)

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::logic_error

Inherited from std::exception

Member functions

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