Workaround MSVC 2015 limitations in Traits.h
authorChristopher Dykes <cdykes@fb.com>
Thu, 16 Feb 2017 22:02:54 +0000 (14:02 -0800)
committerFacebook Github Bot <facebook-github-bot@users.noreply.github.com>
Thu, 16 Feb 2017 22:08:01 +0000 (14:08 -0800)
commit1a8db4b81741a17f8c10e891c16738b744730cc0
tree72a4cf4873541d6a34553b3400e903e3cd2db569
parentdfc2add75af7fa3e32da8566fdb0eeca25366c79
Workaround MSVC 2015 limitations in Traits.h

Summary: MSVC 2015 has issues with templated `using` declarations using `decltype`, so adjust the definition to use constexpr evaluation to fill a template parameter of a base type instead.

Reviewed By: yfeldblum

Differential Revision: D4510155

fbshipit-source-id: cc2e33625b515085dff4e682971299810905fef0
folly/Traits.h