Export symbols on Windows dll builds

include/cppkafka/macros.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2016, Matias Fontanini
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following disclaimer
+ *   in the documentation and/or other materials provided with the
+ *   distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef CPPKAFKA_MACROS_H
+#define CPPKAFKA_MACROS_H
+
+// If cppkafka was built into a shared library
+#if defined(_WIN32) && !defined(CPPKAFKA_STATIC)
+    // Export/import symbols, depending on whether we're compiling or consuming the lib
+    #ifdef cppkafka_EXPORTS
+        #define CPPKAFKA_API __declspec(dllexport)
+    #else
+        #define CPPKAFKA_API __declspec(dllimport)
+    #endif // cppkafka_EXPORTS
+#else 
+    // Otherwise, default this to an empty macro
+    #define CPPKAFKA_API
+#endif // _WIN32 && !CPPKAFKA_STATIC
+
+#endif // CPPKAFKA_MACROS_H