It needs to be used carefully, but has its uses.

C++ Comma Operator

by Ivan Sanz

From the article:

Comma operator has been with us for a long time. First seen in C spec and improved with custom overloads in C++, it quickly became one of those hidden things you shouldn’t use.
Most C/C++ books avoid speaking about goto the same way they do about comma operator. This is not fair, as both of them can be used properly on certain cases. Let’s speak about that...