Provide JSONCPP_DEPRECATED definitions for clang and gcc
diff --git a/include/json/config.h b/include/json/config.h
index f14aaa8..5a2558d 100644
--- a/include/json/config.h
+++ b/include/json/config.h
@@ -70,6 +70,11 @@
#if defined(_MSC_VER) && _MSC_VER >= 1500 // MSVC 2008
/// Indicates that the following function is deprecated.
#define JSONCPP_DEPRECATED(message) __declspec(deprecated(message))
+#elif (defined(__clang__) && __has_attribute(deprecated)) || \
+ (defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)))
+#define JSONCPP_DEPRECATED(message) __attribute__ ((deprecated(message)))
+#elif defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
+#define JSONCPP_DEPRECATED(message) __attribute__((__deprecated__))
#endif
#if !defined(JSONCPP_DEPRECATED)