std::bad_alloc
<new>
std::bad_alloc is the type of the object thrown as exceptions by the allocation functions to report failure to allocate storage.
Inheritance diagram
Contents
[edit] Member functions
bad_alloc object (public member function)
bad_alloc object (public member function)
(public member function)
std::bad_alloc::bad_alloc
(constexpr since C++26)
(constexpr since C++26)
Constructs a new bad_alloc object with an implementation-defined null-terminated byte string which is accessible through what().
std::bad_alloc then std::strcmp (what(), other.what()) == 0.(since C++11)Parameters
std::bad_alloc::operator=
(constexpr since C++26)
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
Return value
*this
std::bad_alloc::what
(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 std::wstring . 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 std::exception
Member functions
[edit] Notes
| Feature-test macro | Value | Std | Feature |
|---|---|---|---|
__cpp_lib_constexpr_exceptions |
202411L |
(C++26) | constexpr for exception types |
[edit] 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