+ small optimization - pass and return const ref

2013-05-07 16:12:57 +01:00 · 2013-05-07 16:12:57 +01:00 · b086e2d20c
commit b086e2d20c
parent 4915bf138e
1 changed files with 1 additions and 1 deletions
--- a/include/mapnik/expression_evaluator.hpp
+++ b/include/mapnik/expression_evaluator.hpp
@ -47,7 +47,7 @@ struct evaluate : boost::static_visitor<T1>
    explicit evaluate(feature_type const& f)
        : feature_(f) {}

-    value_type operator() (value_type x) const
+    value_type const& operator() (value_type const& x) const
    {
        return x;
    }