X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=blobdiff_plain;f=source%2Ftag.h;h=28b4fa010e8b0f12980df476f7ac8160a2c922fb;hp=87d4af656d9a8cea87969f7c966ac6d74d7fb26e;hb=e1e69c49b7727223a43cdc2deac4f1c03a3e3aba;hpb=c6aea1bc1586ffef132e6fffdf99343cb56617db

diff --git a/source/tag.h b/source/tag.h
index 87d4af65..28b4fa01 100644
--- a/source/tag.h
+++ b/source/tag.h
@@ -6,6 +6,10 @@
 namespace Msp {
 namespace GL {
 
+/**
+Provides transparent string-to-hash conversion for faster comparison.  An empty
+string is guaranteed to have an id of 0.
+*/
 struct Tag
 {
 	unsigned id;
@@ -13,6 +17,9 @@ struct Tag
 	Tag(): id(0) { }
 	Tag(const char *);
 	Tag(const std::string &s);
+
+	bool operator<(const Tag &t) const { return id<t.id; }
+	bool operator==(const Tag &t) const { return id==t.id; }
 };
 
 } // namespace GL