From 87b0be9b6f60b28bc9b5af0800bc8ad38ec07b67 Mon Sep 17 00:00:00 2001
From: Tomas Babej <tomas@tbabej.com>
Date: Fri, 23 Apr 2021 22:48:52 -0400
Subject: [PATCH] performance: Pre-emptively reserve size of the values vector

Each token will add a corresponding Variant into the vector, so we can
avoid the performance penalty connected with dynamic resizes of the
vector.
---
 src/Eval.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Eval.cpp b/src/Eval.cpp
index e96464576..97f0c5ad8 100644
--- a/src/Eval.cpp
+++ b/src/Eval.cpp
@@ -224,6 +224,8 @@ void Eval::evaluatePostfixStack (
 
   // This is stack used by the postfix evaluator.
   std::vector <Variant> values;
+  values.reserve(tokens.size());
+
   for (const auto& token : tokens)
   {
     // Unary operators.