1 files changed, 9 insertions, 5 deletions

diff --git a/external/include/glm/gtx/extend.hpp b/external/include/glm/gtx/extend.hpp
index 26837a8..c456fae 100644
--- a/external/include/glm/gtx/extend.hpp
+++ b/external/include/glm/gtx/extend.hpp
@@ -6,15 +6,19 @@
 /// @defgroup gtx_extend GLM_GTX_extend
 /// @ingroup gtx
 ///
-/// @brief Extend a position from a source to a position at a defined length.
+/// Include <glm/gtx/extend.hpp> to use the features of this extension.
 ///
-/// <glm/gtx/extend.hpp> need to be included to use these functionalities.
+/// Extend a position from a source to a position at a defined length.
 
 #pragma once
 
 // Dependency:
 #include "../glm.hpp"
 
+#ifndef GLM_ENABLE_EXPERIMENTAL
+#	error "GLM: GLM_GTX_extend is an experimental extension and may change in the future. Use #define GLM_ENABLE_EXPERIMENTAL before including it, if you really want to use it."
+#endif
+
 #if GLM_MESSAGES == GLM_MESSAGES_ENABLED && !defined(GLM_EXT_INCLUDED)
 #	pragma message("GLM: GLM_GTX_extend extension included")
 #endif
@@ -26,10 +30,10 @@ namespace glm
 
 	/// Extends of Length the Origin position using the (Source - Origin) direction.
 	/// @see gtx_extend
-	template <typename genType> 
+	template<typename genType>
 	GLM_FUNC_DECL genType extend(
-		genType const & Origin, 
-		genType const & Source, 
+		genType const& Origin,
+		genType const& Source,
 		typename genType::value_type const Length);
 
 	/// @}