Integral promotion and operator+=

Question

I need to eliminate gcc -Wconversion warnings. For example

typedef unsigned short     uint16_t;

uint16_t a = 1;
uint16_t b = 2;
b += a;

gi

Answer 1

You could build your own abstraction to overload the += operator, something like

template 
class myVar {
    public:
    myVar(T var) : val{var} {}
    myVar& operator+=(const myVar& t) { 
        this->val = static_cast(this->val + t.val);
        return *this; 
    }
    T val;
};

int main()
{
    typedef unsigned short     uint16_t;

    myVar c{3};
    myVar d{4};
    c += d;
}

It still uses a static_cast, but you only need to use it once and then reuse it. And you don't need it in your main.

IMHO it just adds overhead, but opinions may vary...