add _ALL_SOURCE as an alias for _GNU_SOURCE/enable-everything

[musl] / include / ctype.h

diff --git a/include/ctype.h b/include/ctype.h
index 8ceaa9f..8f0d168 100644 (file)
--- a/include/ctype.h
+++ b/include/ctype.h
@@ -5,6 +5,8 @@
 extern "C" {
 #endif
 
+#include <features.h>
+
 int   isalnum(int);
 int   isalpha(int);
 int   isblank(int);