From 4f919b83c2cc09d1f0c40c1bf42adb6bd1b721ec Mon Sep 17 00:00:00 2001
From: denchat <19730041+denchat@users.noreply.github.com>
Date: Thu, 2 May 2019 13:32:00 +0700
Subject: [PATCH] Add `FMT_EXTERN_TEMPLATE_API` for designate DLL export
 `extern template`

When exporting DLL, do not designate `__declspec(dllexport)` any template that has any explicit class template declaration a.k.a. `extern template`. Instead, designate `__declspec(dllexport)` at single point where we have explicit class template definition a.k.a. normal instantiation without `extern`

Note: this is a c++11 feature.
---
 include/fmt/core.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/fmt/core.h b/include/fmt/core.h
index 8dc68e40..faeea94f 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -189,11 +189,15 @@
 #    define FMT_API __declspec(dllexport)
 #  elif defined(FMT_SHARED)
 #    define FMT_API __declspec(dllimport)
+#    define FMT_EXTERN_TEMPLATE_API FMT_API
 #  endif
 #endif
 #ifndef FMT_API
 #  define FMT_API
 #endif
+#ifndef FMT_EXTERN_TEMPLATE_API
+#  define FMT_EXTERN_TEMPLATE_API
+#endif
 
 #ifndef FMT_ASSERT
 #  define FMT_ASSERT(condition, message) assert((condition) && message)