From d73fec3f6cc25c049d00754bbe3c0f5aa3bfe399 Mon Sep 17 00:00:00 2001
From: anothersimulacrum <anothersimulacrum@gmail.com>
Date: Wed, 17 Mar 2021 09:48:22 -0700
Subject: [PATCH] Don't copy mutation branches unecessarily

---
 src/mutation_type.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/mutation_type.cpp b/src/mutation_type.cpp
index e1d1531ddc5b2..371c20ddab6fb 100644
--- a/src/mutation_type.cpp
+++ b/src/mutation_type.cpp
@@ -24,7 +24,7 @@ bool mutation_type_exists( const std::string &id )
 std::vector<trait_id> get_mutations_in_type( const std::string &id )
 {
     std::vector<trait_id> ret;
-    for( mutation_branch it : mutation_branch::get_all() ) {
+    for( const mutation_branch &it : mutation_branch::get_all() ) {
         if( it.types.find( id ) != it.types.end() ) {
             ret.push_back( it.id );
         }