use unsigned for wxString [] operator

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@1054 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

diff --git a/include/wx/confbase.h b/include/wx/confbase.h
index 2ce903fec70c0365e0c26fc502399d498f737340..1b51cae5265fde8163ec58c77d2cf3b2ef1f3f8e 100644 (file)
--- a/include/wx/confbase.h
+++ b/include/wx/confbase.h
@@ -222,7 +222,7 @@ public:
 
 protected:
   static bool IsImmutable(const wxString& key)
-    { return key[0] == wxCONFIG_IMMUTABLE_PREFIX; }
+    { return key[0u] == wxCONFIG_IMMUTABLE_PREFIX; }
 
 private:
   // are we doing automatic environment variable expansion?