add a constexpr in c10::Half (#16091)

Summary:
Debug build generates references which are not resolved otherwise

as recognized by dlibenzi
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16091

Differential Revision: D13703584

Pulled By: soumith

fbshipit-source-id: 6ac5666d2c6b1520e083f6eac9c535a1609d9c6b

diff --git a/c10/util/Half.cpp b/c10/util/Half.cpp
index 76e36ea..95ec712 100644 (file)
--- a/c10/util/Half.cpp
+++ b/c10/util/Half.cpp
@@ -4,6 +4,8 @@
 
 namespace c10 {
 
+constexpr Half::from_bits_t Half::from_bits;
+
 static_assert(
     std::is_standard_layout<Half>::value,
     "c10::Half must be standard layout.");