fix: Declare FlagRegisterer c’tor explicit template instanations as extern in header
diff --git a/src/gflags.h.in b/src/gflags.h.in
index 1f1d907..b437862 100644
--- a/src/gflags.h.in
+++ b/src/gflags.h.in
@@ -441,6 +441,23 @@
FlagType* current_storage, FlagType* defvalue_storage);
};
+// Force compiler to not generate code for the given template specialization.
+#define GFLAGS_DECLARE_FLAG_REGISTERER_CTOR(type) \
+ extern template GFLAGS_DLL_DECL FlagRegisterer::FlagRegisterer( \
+ const char* name, const char* help, const char* filename, \
+ type* current_storage, type* defvalue_storage)
+
+// Do this for all supported flag types.
+GFLAGS_DECLARE_FLAG_REGISTERER_CTOR(bool);
+GFLAGS_DECLARE_FLAG_REGISTERER_CTOR(int32);
+GFLAGS_DECLARE_FLAG_REGISTERER_CTOR(uint32);
+GFLAGS_DECLARE_FLAG_REGISTERER_CTOR(int64);
+GFLAGS_DECLARE_FLAG_REGISTERER_CTOR(uint64);
+GFLAGS_DECLARE_FLAG_REGISTERER_CTOR(double);
+GFLAGS_DECLARE_FLAG_REGISTERER_CTOR(std::string);
+
+#undef GFLAGS_DECLARE_FLAG_REGISTERER_CTOR
+
// If your application #defines STRIP_FLAG_HELP to a non-zero value
// before #including this file, we remove the help message from the
// binary file. This can reduce the size of the resulting binary
