std::nothrow

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Defined in header `<new>`

extern const std::nothrow_t nothrow;

std::nothrow is a constant of type std::nothrow_t used to disambiguate the overloads of throwing and non-throwing allocation functions.

[edit] Example

#include <iostream>
#include <new>
int main()
{
    try {
        while(true)
            new int[100000000ul];   // throwing overload
    }catch(const std::bad_alloc& e) {
        std::cout << e.what() << '\n';
    }
 
    while(true)
    {
        int* p = new(std::nothrow) int[100000000ul]; // non-throwing overload
        if(p==NULL)
        {
            std::cout << "Allocation returned NULL\n";
            break;
        }
    }
}

Output:

std::bad_alloc
Allocation returned NULL

[edit] See also


nothrow_t	tag type used to select an non-throwing allocation function (class)

operator new operator new[]	allocation functions (function)