plus use constexpr to define the compile time constant

size_t should be use for container indexes and container related
distances

... 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.

The parents were set incorrectly in swap of trees and tries. Parents in children
of swapped objects should be set, not the parents in swapped objects.

The template function sort internally called swap so it internaly tests
swap of trees

Take out common code in then and else branch

it was replaced with a constraint

methods ext::Variant < ... >::set are joined + refactored to fix the std::move
vs std::forward issue

concepts are language native construct that was introduced to replace enable_if
(SFINAE)

virtual should start dynamic binding override checks dynamic binding is enabled
in base class

_identifiers are reserved for use for instance in the standard library

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).