add: stackPtr = stack;
context: vmachine::execute(int code[]){    int const*  pc = code;    bool        running = true;    while (running)    {        switch (*pc++)        {            case OP_NEG:                stackPtr[-1] = -stackPtr[-1];                break;            case OP_ADD:                stackPtr--;                stackPtr[-1] += stackPtr[0];                break;            case OP_SUB:                stackPtr--;                stackPtr[-1] -= stackPtr[0];                break;            case OP_MUL:                stackPtr--;                stackPtr[-1] *= stackPtr[0];                break;            case OP_DIV:                stackPtr--;                stackPtr[-1] /= stackPtr[0];                break;            case OP_INT:                // Check stack overflow here!                *stackPtr++ = *pc++;                break;            case OP_RET:                running = false;                break;        }    }}