C++11/14/17 std::expected with functional-style extensions
tl-expected is a single header implementation of `std::expected` with
functional-style extensions.

std::expected is proposed as the preferred way to represent an object which
will either have an expected value, or an unexpected value giving
information about why something failed.  Unfortunately, chaining together
many computations which may fail can be verbose, as error-checking code will
be mixed in with the actual programming logic.  This implementation provides
a number of utilities to make coding with expected cleaner.

Maintainer: Klemens Nanni <kn@openbsd.org>

WWW: https://tl.tartanllama.xyz
