abstraction: make type-fixed ObjectFactoryImpl's not inlined + extern a common templated instantiation

Closes #49

unique ptr is convertible to shared ptr natively. It makes sense to construct
unique_ptr first and convert it to shared_ptr if it is needed.

Most likely a remnant of abstraction refactoring to OperationAbstraction and
Value where Value is using the functionality, not the OperationAbstraction

std::result_of is deprecated in C++17

Jan Trávníček authored 3 years ago and Jan Trávníček committed 3 years ago

breaking change!

While working on webui, I have noticed that exports from
automata-library contain for many algorithms documentation set to
string "Documentation not available.". I traced the problem back to this
project.

I do not think "Documentation not available" is itself a valid
documentation of an algorithm so I decided to replace the std::string
that is supposed to hold documentation of an overload with an
std::optional<std::string>. The semantics should now be clearer.

While working on a webui I noticed that some algos have documentation
set to "Documentation not avaiable" instead of available. That's a typo
with multiple occurrences throughout the project.

... 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.

moving is actually more expensive for shared_ptrs

primitive types don't need std::move

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