The use of double include guards in C++

Question

So I recently had a discussion where I work, in which I was questioning the use of a double include guard over a single guard. What I mean by double gua

Answer 1

Although there are people arguing against it, in practice '#pragma once' works perfectly and the main compilers (gcc/g++, vc++) support it.

So whatever puristic argumentation people are spreading, it works a lot better:

1. Fast
2. No maintenance, no trouble with mysterious non-inclusion because you copied an old flag
3. Single line with obvious meaning versus cryptic lines spread in file

So simply put:

#pragma once

at the start of the file, and that's it. Optimized, maintainable, and ready to go.