It is better to manage warnings on our side to know what warnings we need to fix or suppress, and the only thing that header does is disabling deprecation warnings on MSVC and ICC which we would prefer to not show to users.
Include needed parts at place where they are needed instead of including the
whole Proto library and significant parts of Phoenix in a few places.
Parsing time reported by Clang 9 with default (C++14) std:
was |now |gain|include
----|----|----|----------
4.45|4.22|5.2%|qi
4.52|4.23|7.5%|karma
4.37|3.99|9.7%|lex
3.75|3.47|7.5%|qi_numeric
There were phoenix/limits.hpp inclusion before every Proto inclusion to override
Proto limits with Phoenix limits values. It has no value in C++11+ world, and
poisons code too much as the number of places where Proto headers now included
increased, so I did not replicate it.
