[PATCH] D16751: Enable constexpr on Visual Studio 2015, add support for two equivalent attributes

[Aaron Ballman via llvm-commits]

aaron.ballman added reviewers: rnk, majnemer.
aaron.ballman added subscribers: majnemer, rnk.
aaron.ballman added a comment.

Generally LGTM, but adding @rnk and @majnemer for an extra opinion on MSVC's constexpr-readiness.


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Comment at: C:/LLVM/llvm/include/llvm/Support/Compiler.h:95
@@ -94,3 +94,3 @@
 
-#if __has_feature(cxx_constexpr) || defined(__GXX_EXPERIMENTAL_CXX0X__)
+#if __has_feature(cxx_constexpr) || defined(__GXX_EXPERIMENTAL_CXX0X__) || LLVM_MSC_PREREQ(1900)
 # define LLVM_CONSTEXPR constexpr
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I think this is reasonable, but we may still get some failures depending on usage. MSVC's constexpr support is drastically improved in MSVC 2015, but is not C++14 constexpr, it's C++11 constexpr.


http://reviews.llvm.org/D16751