Patch for windows llvm clang

[duckie]

I put the pull request here so it runs through Travis.

See #2 for details.

[codecov-io]

Codecov Report

Merging #3 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master     #3   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files          18     18           
  Lines         560    585   +25     
  Branches        2      0    -2     
=====================================
+ Hits          560    585   +25

Impacted Files	Coverage Δ
includes/named_types/rt_named_tag.hpp	100% <ø> (ø)	⬆️
includes/named_types/named_tag.hpp	100% <ø> (ø)	⬆️
includes/named_types/literals/string_literal.hpp	100% <ø> (ø)	⬆️
includes/named_types/extensions/factory.hpp	100% <100%> (ø)	⬆️
includes/named_types/rt_named_tuple.hpp	100% <100%> (ø)	⬆️
includes/named_types/named_tuple.hpp	100% <100%> (ø)	⬆️
includes/std/experimental/tagged.hpp	100% <100%> (ø)	⬆️
includes/named_types/extensions/parsing_tools.hpp	100% <100%> (ø)	⬆️
test/demo2.cc	100% <0%> (ø)	⬆️
test/demo4.cc	100% <0%> (ø)	⬆️
... and 8 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ffd3a6c...b6bb522. Read the comment docs.