headers: check that _GL_INLINE_HEADER_BEGIN is defined

[gnulib.git] / lib / gl_xoset.h

diff --git a/lib/gl_xoset.h b/lib/gl_xoset.h
index 7ab0d49..b30b2ce 100644 (file)
--- a/lib/gl_xoset.h
+++ b/lib/gl_xoset.h
@@ -21,6 +21,9 @@
 #include "gl_oset.h"
 #include "xalloc.h"
 
+#ifndef _GL_INLINE_HEADER_BEGIN
+ #error "Please include config.h first."
+#endif
 _GL_INLINE_HEADER_BEGIN
 #ifndef GL_XOSET_INLINE
 # define GL_XOSET_INLINE _GL_INLINE