Cast month numbers to the correct type in date parsing map init

[Lastique]

Since the map contains unsigned short for month numbers, it is more correct to explicitly cast constants to that type rather than short.

[codecov[bot]]

Codecov Report

Merging #152 into develop will not change coverage. The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop     #152   +/-   ##
========================================
  Coverage    52.72%   52.72%           
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  Files           76       76           
  Lines         4491     4491           
  Branches      2243     2243           
========================================
  Hits          2368     2368           
  Misses         391      391           
  Partials      1732     1732           

Impacted Files	Coverage Δ
include/boost/date_time/date_parsing.hpp	33.01% <ø> (ø)

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[mclow]

That's amazingly ugly. This is because of https://stackoverflow.com/questions/61552098/boost-1-73-log-library-regression, isn't it?

I stand by my comment that this is the compiler being silly.

[Lastique]

I totally agree that the compiler should not emit that warning. However, if we do the cast, we should cast to the right type.

[mclow]

I concur 100%. IMHO, we should remove the casts and suppress the warning.

[JeffGarland]

although I agree the compiler is silly it's not worth more intellectual effort at this point so just merging it.

[mclow]

I've spoken to a MS compiler dev, and he's opened a bug against MSVC for this behavior.

[JeffGarland]

wow nice! anyway we can get notified when it is fixed?