Made JSON_USE_EXCEPTION's value in config.h a default that can be overridden.
This allows users to override it with their compiler invocation. For example:
g++ -D JSON_USE_EXCEPTION=0 ...
diff --git a/include/json/assertions.h b/include/json/assertions.h
index 5a27d5f..84eb5d7 100644
--- a/include/json/assertions.h
+++ b/include/json/assertions.h
@@ -13,10 +13,10 @@
# include <json/config.h>
#endif // if !defined(JSON_IS_AMALGAMATION)
-#if defined(JSON_USE_EXCEPTION)
+#if JSON_USE_EXCEPTION
#define JSON_ASSERT( condition ) assert( condition ); // @todo <= change this into an exception throw
#define JSON_FAIL_MESSAGE( message ) throw std::runtime_error( message );
-#else // defined(JSON_USE_EXCEPTION)
+#else // JSON_USE_EXCEPTION
#define JSON_ASSERT( condition ) assert( condition );
#define JSON_FAIL_MESSAGE( message ) { std::cerr << std::endl << message << std::endl; exit(123); }
#endif