Templates are not quite side-effect free, although it takes some effort to run into that. See http://b.atch.se/posts/constexpr-counter/ http://b.atch.se/posts/c

Templates are not quite side-effect free, although it takes some effort to run into that. See http://b.atch.se/posts/constexpr-counter/ http://b.atch.se/posts/constexpr-counter/ for a delicious exploit of that fact.