cross-DLL TraitKey duplication on Windows via explicit template instantiation

Author: pulimsr

src/aws-cpp-sdk-core/include/smithy/client/schema/JsonTraits.h

@@ -21,5 +21,7 @@ class JsonNameTrait : public Trait {
   Aws::String m_value;
 };
 
+extern template class TraitKey<JsonNameTrait>;
+
 }  // namespace schema
 }  // namespace smithy

src/aws-cpp-sdk-core/include/smithy/client/schema/SerdeTraits.h

@@ -22,5 +22,7 @@ class TimestampFormatTrait : public Trait {
   Format m_format;
 };
 
+extern template class TraitKey<TimestampFormatTrait>;
+
 }  // namespace schema
 }  // namespace smithy

src/aws-cpp-sdk-core/include/smithy/client/schema/TraitKey.h

@@ -20,10 +20,7 @@ SMITHY_API int NextTraitKey();
 template <typename T>
 class TraitKey : public TraitKeyBase {
  public:
-  static const TraitKey& Instance() {
-    static const TraitKey instance(NextTraitKey());
-    return instance;
-  }
+  static const TraitKey& Instance();
 
  private:
   explicit TraitKey(int id) : TraitKeyBase(id) {}

src/aws-cpp-sdk-core/include/smithy/client/schema/XmlTraits.h

@@ -83,5 +83,14 @@ class XmlMapValueNameTrait : public Trait {
   Aws::String m_value;
 };
 
+extern template class TraitKey<XmlNameTrait>;
+extern template class TraitKey<XmlFlattenedTrait>;
+extern template class TraitKey<XmlAttributeTrait>;
+extern template class TraitKey<XmlNamespaceTrait>;
+extern template class TraitKey<XmlListItemNameTrait>;
+extern template class TraitKey<XmlMapEntryNameTrait>;
+extern template class TraitKey<XmlMapKeyNameTrait>;
+extern template class TraitKey<XmlMapValueNameTrait>;
+
 }  // namespace schema
 }  // namespace smithy

src/aws-cpp-sdk-core/source/smithy/client/schema/TraitKey.cpp

@@ -1,4 +1,11 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#include <smithy/client/schema/JsonTraits.h>
+#include <smithy/client/schema/SerdeTraits.h>
 #include <smithy/client/schema/TraitKey.h>
+#include <smithy/client/schema/XmlTraits.h>
 
 #include <atomic>
 
@@ -8,5 +15,23 @@ namespace schema {
 static std::atomic<int> s_traitIdCounter{0};
 
 int NextTraitKey() { return s_traitIdCounter.fetch_add(1, std::memory_order_relaxed); }
+
+template <typename T>
+const TraitKey<T>& TraitKey<T>::Instance() {
+  static const TraitKey instance(NextTraitKey());
+  return instance;
+}
+
+template class TraitKey<JsonNameTrait>;
+template class TraitKey<TimestampFormatTrait>;
+template class TraitKey<XmlNameTrait>;
+template class TraitKey<XmlFlattenedTrait>;
+template class TraitKey<XmlAttributeTrait>;
+template class TraitKey<XmlNamespaceTrait>;
+template class TraitKey<XmlListItemNameTrait>;
+template class TraitKey<XmlMapEntryNameTrait>;
+template class TraitKey<XmlMapKeyNameTrait>;
+template class TraitKey<XmlMapValueNameTrait>;
+
 }  // namespace schema
-}  // namespace smithy
+}  // namespace smithy