NAME¶

std::out_of_range - std::out_of_range

Synopsis¶

Defined in header <stdexcept>
class out_of_range;

Defines a type of object to be thrown as exception. It reports errors that are
consequence of attempt to access elements out of defined range.

It may be thrown by the member functions of std::bitset and std::basic_string, by
std::stoi and std::stod families of functions, and by the bounds-checked member
access functions (e.g. std::vector::at and std::map::at).

std-out of range-inheritance.svg

Inheritance diagram

Member functions¶

constructor constructs a new out_of_range object with the given message
(public member function)
operator= replaces the out_of_range object
(public member function)

std::out_of_range::out_of_range

out_of_range( const std::string& what_arg ); (1)
out_of_range( const char* what_arg ); (2)
out_of_range( const out_of_range& 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::out_of_range
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::out_of_range 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::out_of_range::operator=

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

Assigns the contents with those of other. If *this and other both have dynamic type
std::out_of_range 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 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::logic_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)

Notes¶

The standard error condition std::errc::result_out_of_range typically indicates the
condition where the result, rather than the input, is out of range, and is more
closely related to std::range_error and ERANGE.

Defect reports

The following behavior-changing defect reports were applied retroactively to
previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 254 C++98 the constructor accepting const char* added
was missing
the explanatory strings of they are the same as that
LWG 471 C++98 std::out_of_range's of the
copies were implementation-defined original std::out_of_range
object

See also¶

at accesses the specified character with bounds checking
(public member function of std::basic_string<CharT,Traits,Allocator>)
at accesses the specified character with bounds checking
(public member function of std::basic_string_view<CharT,Traits>)
at access specified element with bounds checking
(public member function of std::deque<T,Allocator>)
at access specified element with bounds checking
(public member function of std::map<Key,T,Compare,Allocator>)
access specified element with bounds checking
at (public member function of
std::unordered_map<Key,T,Hash,KeyEqual,Allocator>)
at access specified element with bounds checking
(public member function of std::vector<T,Allocator>)
at access specified element with bounds checking
(public member function of std::array<T,N>)
at access specified element with bounds checking
(C++26) (public member function of std::span<T,Extent>)