1 files changed, 4 insertions, 0 deletions
diff --git a/src/Block.cpp b/src/Block.cpp
index 840dbcf..667670d 100644
--- a/src/Block.cpp
+++ b/src/Block.cpp
@@ -8,4 +8,8 @@ Block::Block() : id(0), state(0), light(0), sky(0) {}
 
 bool operator==(const BlockId& lhs, const BlockId &rhs) {
     return (lhs.id == rhs.id) && (lhs.state == rhs.state);
+}
+
+bool operator<(const BlockId& lhs, const BlockId &rhs) {
+    return (lhs.id < rhs.id);
 }
 \ No newline at end of file