Question

As I’m coding for both Windows and Linux, I have a whole host of problems.
Microsoft Visual C++ has no stdint header, but for that I wrote my own.

Now I found out that MS C++’s new operator does not throw an exception, so I want to fix this a quickly as possible. I know I can define a Macro with Parameters in Parenthesis, can I define a macro that replaces

MyClass x = new MyClass();

with

#ifdef MSC_VER
if(!(MyClass x = new MyClass())
{
    throw new std::bad_alloc();
}
#else
MyClass x = new MyClass();
#endif

(or something equivalent), AND works in BOTH MS C++ and G++ ?

Or alternatively if that is not possible, a batch file to run over the Code to do this?
I have become rather dependent on this exception being thrown.

Answer 1

The simplest alternative is to write your own implementation of operator new, overriding the compiler’s default implementation (if your version of MSVC supports it). This is what Roger also suggested in his linked answer.

The following program illustrates the attempt. operator new allocates memory from the heap using malloc and free. If you’re doing conditional compilation for G++ and MSVC, you can also use HeapAlloc and HeapFree instead of malloc and free for a more WinAPI-oriented approach.

#include <iostream>
#include <cstdlib>

void *operator new(unsigned int size) throw (std::bad_alloc) {
    void *ptr = malloc(size);

    if (!ptr)
        throw std::bad_alloc();
    return ptr;
}

void operator delete(void *ptr) throw () {
    free(ptr);
}

// Sample code to test the implementation.
int main(int argc, char **argv) {
    int *values[10];

    for (int i = 0; i < 10; ++i)
        values[i] = new int(i);
    for (int i = 0; i < 10; ++i)
        std::cout << *values[i] << std::endl;
    for (int i = 0; i < 10; ++i)
        delete values[i];
    return 0;
}