std::bad_alloc

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Dynamic memory management
Uninitialized storage
(C++17)
Garbage collection support
Miscellaneous
(C++20)
(C++11)
(C++11)
C Library
Low level memory management
Defined in header <new>
class bad_alloc;

std::bad_alloc is the type of the object thrown as exceptions by the allocation functions to report failure to allocate storage.

cpp/error/exceptionstd-bad alloc-inheritance.svg

Inheritance diagram

Member functions

(constructor)
constructs the bad_alloc object
(public member function)
operator=
replaces a bad_alloc object
(public member function)
what
returns explanatory string
(public member function)

std::bad_alloc::bad_alloc

bad_alloc();

Constructs new bad_alloc object with an implementation-defined null-terminated byte string which is accessible through what().

Parameters

(none)

Exceptions

(none) (until C++11)
noexcept specification:
noexcept
(since C++11)

std::bad_alloc::operator=

bad_alloc& operator=( const bad_alloc& other );

Assigns the contents of other.

Parameters

other - another exception object to assign

Return value

*this

Exceptions

(none) (until C++11)
noexcept specification:
noexcept
(since C++11)

std::bad_alloc::what

virtual const char* what() const;

Returns the explanatory string.

Parameters

(none)

Return value

Pointer to a null-terminated string with explanatory information.

Exceptions

(none) (until C++11)
noexcept specification:
noexcept
(since C++11)

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)

Example

#include <iostream>
#include <new>

int main()
{
    try {
        while (true) {
            new int[100000000ul];
        }
    } catch (const std::bad_alloc& e) {
        std::cout << "Allocation failed: " << e.what() << '\n';
    }
}

Possible output:

Allocation failed: std::bad_alloc

See also

allocation functions
(function)