Printing lists with commas C++

Question

I know how to do this in other languages, but not C++, which I am forced to use here.

I have a Set of Strings that I\'m printing to out in a list, and they need a co

Answer 1

A combination of c++11 lambda and macro:

#define INFIX_PRINTER(os, sep)([&]()->decltype(os)&{static int f=1;os<<(f?(f=0,""):sep);return os;})()

Usage:

for(const auto& k: keywords)
    INFIX_PRINTER(out, ", ") << k;