From cppreference.com
Defines a type of object to be thrown as exception. It reports errors that result from attempts to exceed implementation defined length limits for some object.
This exception is thrown by member functions of
and
.
Inheritance diagram
Member functions
(constructor)
constructs a new length_error object with the given message
(public member function)operator=
replaces the length_error object
(public member function)std::length_error::length_error
length_error(conststd::string&what_arg); (1) length_error(constchar*what_arg); (2) length_error(constlength_error&other); (3) (noexcept since C++11)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::length_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
Notes
Because copying std::length_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
, the non-copy constructor can only accept
. It makes dynamic allocation mandatory in order to construct a
object.
After the resolution of
, 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::length_error::operator=
length_error&operator=(constlength_error&other);(noexcept since C++11)Assigns the contents with those of other. If *this and other both have dynamic type std::length_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
After the resolution of
, 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
Inherited from
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
C++98 the constructor accepting constchar* was missing added
C++98 the explanatory strings of std::length_error's
copies were implementation-defined they are the same as that of the
original std::length_error object See also
changes the number of characters stored
(public member function of std::basic_string<CharT,Traits,Allocator>)