Hacker News Reader

I always thought of it as (only) two pluses, just differently arranged (diagonally overlapped).

Yeah but I think the idea is that it's (C++)++, i.e., the version that comes after C++ (which is the version that comes after C).

Which does not compile in C++ or C# :)

Only because postincrement returns an rvalue. (++C)++ would be valid :)