std::nothrow

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.

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 == nullptr) {
            std::cout << "Allocation returned nullptr\n";
            break;
        }
    }
}

Output:

std::bad_alloc
Allocation returned nullptr

nothrow_t	tag type used to select an non-throwing allocation function (class)
operator newoperator new[]	allocation functions (function)

std::nothrow

Example

See also