The class describes an exception thrown to indicate that an allocation request did not succeed.
class bad_alloc : public exception {
   bad_alloc(const char *_Message);
   bad_alloc();
   virtual ~bad_alloc();
};
Remarks
An instance of bad_alloc can be constructed from a message or from a message string with no memory allocation.
The value returned by what is an implementation-defined C string. None of the member functions throw any exceptions.
Requirements
Header: <new>
Namespace: std
Example
// bad_alloc.cpp
// compile with: /EHsc
#include<new>
#include<iostream>
using namespace std;
int main() {
   char* ptr;
   try {
      ptr = new char[(~unsigned int((int)0)/2) - 1];
      delete[] ptr;
   }
   catch( bad_alloc &ba) {
      cout << ba.what( ) << endl;
   }
}
Sample Output
bad allocation
Requirements
Header: <new>
See Also
Reference
Thread Safety in the Standard C++ Library