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.

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).

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

The register class should have explicit constructors, the member variable data should
be initialized in the member initializer list, should be named m_data, and the
finish callback should accept the data by const reference

tailing return type specification caused infinite template instantiation

It really makes no sense to have it inside alib2std component. Moved
into separate tests/ folder.