std::range_error
Defined in header <stdexcept>
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class range_error; |
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Defines a type of object to be thrown as exception. It can be used to report range errors (that is, situations where a result of a computation cannot be represented by the destination type).
The only standard library components that throw this exception are std::wstring_convert::from_bytes and std::wstring_convert::to_bytes.
The mathematical functions in the standard library components do not throw this exception (mathematical functions report range errors as specified in math_errhandling).
Inheritance diagram
Member functions
(constructor) |
constructs a new range_error object with the given message (public member function) |
operator= |
replaces the range_error object (public member function) |
std::range_error::range_error
range_error( const std::string& what_arg ); |
(1) | |
range_error( const char* what_arg ); |
(2) | |
(3) | ||
range_error( const range_error& other ); |
(until C++11) | |
range_error( const range_error& other ) noexcept; |
(since C++11) | |
std::range_error
then std::strcmp(what(), other.what()) == 0. No exception can be thrown from the copy constructor. (until C++11)Parameters
what_arg | - | explanatory string |
other | - | another exception object to copy |
Exceptions
Notes
Because copying std::range_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.
Before the resolution of LWG issue 254, the non-copy constructor can only accept std::string. It makes dynamic allocation mandatory in order to construct a std::string object.
After the resolution of LWG issue 471, 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::range_error::operator=
range_error& operator=( const range_error& other ); |
(until C++11) | |
range_error& operator=( const range_error& other ) noexcept; |
(since C++11) | |
Assigns the contents with those of other. If *this and other both have dynamic type std::range_error
then std::strcmp(what(), other.what()) == 0 after assignment. No exception can be thrown from the copy assignment operator. (until C++11)
Parameters
other | - | another exception object to assign with |
Return value
*this
Notes
After the resolution of LWG issue 471, 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 ) |
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR | Applied to | Behavior as published | Correct behavior |
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LWG 254 | C++98 | the constructor accepting const char* was missing | added |
LWG 471 | C++98 | the explanatory strings of std::range_error 'scopies were implementation-defined |
they are the same as that of the original std::range_error object
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