How can I explain this while-loop?

[Hung Nguyen Danh]

I have an C++ source code and I have to convert it into C#. But in C++, there's a strange while loop that I can not understand.

while(m_get(&mr,&ml,&mx,&my),id){
   (while body)
}

m_get is a void function that return mouse in formation.
id is an unsigned short type.

Can you help me to explain this while loop.

Thank you,

[long double main]

I'm pretty sure that code is equivalent to

while (true)
{
    m_get(&mr, &ml, &mx, &my);
    if (id)
    {
        // (while body)
    }
    else
        break;
}

(You can write it a couple of different ways).

Basically, the line m_get(&mr,&ml,&mx,&my),id first does m_get(&mr,&ml,&mx,&my) and then returns the value of id.

There's a little explanation on the comma operator here:
http://www.cplusplus.com/doc/tutorial/operators/
(Just do a search for "Comma operator" on that page and you'll find it).

[Hung Nguyen Danh]

Thank you long double main!

I'll try this.