From 8ecc2cf71bc6268b8fb15b9e3d09a3944e0e2e44 Mon Sep 17 00:00:00 2001
From: John Fletcher <J.P.Fletcher@aston.ac.uk>
Date: Sun, 11 Jan 2015 00:39:52 +0000
Subject: [PATCH] scope/let.hpp Make a local copy of vars and use it.

---
 include/boost/phoenix/scope/let.hpp | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/include/boost/phoenix/scope/let.hpp b/include/boost/phoenix/scope/let.hpp
index 6899c99..ece33e4 100644
--- a/include/boost/phoenix/scope/let.hpp
+++ b/include/boost/phoenix/scope/let.hpp
@@ -10,8 +10,8 @@
 #ifndef BOOST_PHOENIX_SCOPE_LET_HPP
 #define BOOST_PHOENIX_SCOPE_LET_HPP
 
-#include <boost/assert.hpp>
-#include <sstream>
+//#include <boost/assert.hpp>
+//#include <sstream>
 #include <boost/phoenix/core/limits.hpp>
 #include <boost/fusion/include/transform.hpp>
 #include <boost/fusion/include/as_vector.hpp>
@@ -88,6 +88,8 @@ namespace boost { namespace phoenix
         typename result<let_eval(Vars const&, Map const&, Expr const &, Context const &)>::type const
         operator()(Vars const & vars, Map, Expr const & expr, Context const & ctx) const
         {
+            Vars vars_(vars);
+
             typedef
                 typename proto::detail::uncvref<
                     typename result_of::env<Context>::type
@@ -111,7 +113,7 @@ namespace boost { namespace phoenix
                 >::type
             locals_type;
 
-            locals_type locals = initialize_locals(proto::value(vars), ctx);
+            locals_type locals = initialize_locals(proto::value(vars_), ctx);
 
             scoped_environment<
                 env_type
@@ -123,11 +125,11 @@ namespace boost { namespace phoenix
 
             // Fix for bugs (trial)
             // The idea is to do something which will not be optimised away.
-            int vsize = boost::fusion::size(vars);
-            std::stringstream strm;
-            strm << vsize << std::endl;
-            int size = strm.str().length();
-            BOOST_ASSERT(size >= 0);
+            //int vsize = boost::fusion::size(vars);
+            //std::stringstream strm;
+            //strm << vsize << std::endl;
+            //int size = strm.str().length();
+            //BOOST_ASSERT(size >= 0);
             return eval(expr, phoenix::context(env, phoenix::actions(ctx)));
         }
     };