<new> functions
The latest version of this topic can be found at <new> functions.
| nothrow | set_new_handler |
nothrow
Provides an object to be used as an argument for the nothrow versions of new and delete.
extern const std::nothrow_t nothrow;
Remarks
The object is used as a function argument to match the parameter type std::nothrow_t.
Example
See operator new and operator new[] for examples of how std::nothrow_t is used as a function parameter.
set_new_handler
Installs a user function that is to be called when operator new fails in its attempt to allocate memory.
new_handler set_new_handler(new_handler _Pnew) throw();
Parameters
_Pnew
The new_handler to be installed.
Return Value
0 on the first call and the previous new_handler on subsequent calls.
Remarks
The function stores _Pnew in a static new handler pointer that it maintains, then returns the value previously stored in the pointer. The new handler is used by operator new( size_t).
Example
// new_set_new_handler.cpp
// compile with: /EHsc
#include<new>
#include<iostream>
using namespace std;
void __cdecl newhandler( )
{
cout << "The new_handler is called:" << endl;
throw bad_alloc( );
return;
}
int main( )
{
set_new_handler (newhandler);
try
{
while ( 1 )
{
new int[5000000];
cout << "Allocating 5000000 ints." << endl;
}
}
catch ( exception e )
{
cout << e.what( ) << endl;
}
}
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
Allocating 5000000 ints.
The new_handler is called:
bad allocation