... because most developers were copy-pasting the preambule anyway and
did not pay any attention to change it.

Also, I think that git does better job in managing that.

remove unnecessary move of an integral value, add const qualifier to a method
that does not change the this object and remove another use of _identifier

Tomáš Pecka authored 4 years ago and Jan Trávníček committed 4 years ago

Although #pragma once is not a standard, compilers nowadays usually
support it. We don't have any tricky build system so we should be OK.

This also fixes many errors regarding using reserved identifiers (names
starting with double underscore).

removal of an unnecessary recursion, addition of forgotten move, removal of
unnecessary const qualifier, change int to -> size_t

Explicit constructors, transform, and any_of