Could I use the Overloaded 'new' operator with original 'new ' together?

I have wrote a cpp as follow to overload the new operator.

    void* operator new(size_t size)
{
    //return malloc(size);
    return MemoryMgr::Instance().allocMem(size); 
}


void operator delete(void* p)
{
    MemoryMgr::Instance().freeMem(p);
}

void* operator new[](size_t size)
{
    return MemoryMgr::Instance().allocMem(size);
}


void operator delete[](void* p)
{
    MemoryMgr::Instance().freeMem(p);
}


void* mem_alloc(size_t size)
{
    return MemoryMgr::Instance().allocMem(size);
}

void mem_free(void* p)
{
    free(p);
}

However, in the main function, sometime I want to ues original new. But the computer always calls the overloaded new. Then I have tried the ::new.But it doesn't make sense. Which way that I can use both overloaded new and original new ? Put the void* operator new in a specialized class which need to be overload new function?