From cppreference.com
Defined in header
classbad_alloc;std::bad_alloc is the type of the object thrown as exceptions by the
to report failure to allocate storage.
Inheritance diagram
Member functions
(constructor)
constructs a new bad_alloc object
(public member function)operator=
replaces the bad_alloc object
(public member function)what
returns the explanatory string
(public member function)std::bad_alloc::bad_alloc
bad_alloc()throw(); (1)(until C++11)bad_alloc()noexcept;(since C++11)bad_alloc(constbad_alloc&other)throw(); (2)(until C++11)bad_alloc(constbad_alloc&other)noexcept;(since C++11)Constructs a new bad_alloc object with an implementation-defined null-terminated byte string which is accessible through
.
1) Default constructor.
2) Copy constructor. If *this and other both have dynamic type std::bad_alloc then std::strcmp(what(),other.what())==0.(since C++11)
Parameters
other - another exception object to copy std::bad_alloc::operator=
bad_alloc&operator=(constbad_alloc&other)throw();(until C++11)bad_alloc&operator=(constbad_alloc&other)noexcept;(since C++11)Assigns the contents with those of other. If *this and other both have dynamic type std::bad_alloc then std::strcmp(what(),other.what())==0 after assignment.(since C++11)
Parameters
other - another exception object to assign with Return value
*this
std::bad_alloc::what
virtualconstchar*what()constthrow();(until C++11)virtualconstchar*what()constnoexcept;(since C++11)
(constexpr since C++26)Returns the explanatory string.
Return value
Pointer to an implementation-defined null-terminated string with explanatory information. The string is suitable for conversion and display as a
. 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.
The returned string is encoded with the ordinary literal encoding during constant evaluation.
(since C++26)Notes
Implementations are allowed but not required to override what().
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)
Notes
macroValueStdFeature
__cpp_lib_constexpr_exceptions
(C++26)constexpr for exception types Example
Run this code
#include<iostream>#include<new>intmain(){try{while(true){newint[100000000ul];}}catch(conststd::bad_alloc&e){std::cout<<"Allocation failed: "<<e.what()<<'\n';}}Possible output:
Allocation failed: std::bad_alloc See also