From 31ef683cedd35fb0ff10094f7c7649b97832b86d Mon Sep 17 00:00:00 2001
From: Jason Turner <jason@emptycrate.com>
Date: Mon, 12 Jan 2015 10:06:42 -0700
Subject: [PATCH] Use SFINAE to clean up divide by zero protection

---
 .../chaiscript/dispatchkit/boxed_number.hpp   | 22 +++++--------------
 unittests/future.chai                         |  6 ++---
 2 files changed, 7 insertions(+), 21 deletions(-)

diff --git a/include/chaiscript/dispatchkit/boxed_number.hpp b/include/chaiscript/dispatchkit/boxed_number.hpp
index c00911c..a0ad6aa 100644
--- a/include/chaiscript/dispatchkit/boxed_number.hpp
+++ b/include/chaiscript/dispatchkit/boxed_number.hpp
@@ -49,32 +49,20 @@ namespace chaiscript
   class Boxed_Number
   {
     private:
-#ifndef CHAISCRIPT_NO_PROTECT_DIVIDEBYZERO
       template<typename T>
-      static void check_divide_by_zero(T t)
+      static void check_divide_by_zero(T t, typename std::enable_if<std::is_integral<T>::value>::type* = 0)
       {
-
-#ifdef CHAISCRIPT_MSVC
-        // MSVC complains that this expression is both constant and the value t is unused
-        // in the cases of integral expressions. Seems a bit overzealous to me, the parameter
-        // is only unreferenced because they are eliminating the dead code.
-#pragma warning(push)
-#pragma warning(disable : 4100 4127)
-#endif
-        if(std::is_integral<T>::value && std::is_arithmetic<T>::value && t==0) {
+#ifndef CHAISCRIPT_NO_PROTECT_DIVIDEBYZERO
+        if (t == 0) {
           throw chaiscript::exception::arithmetic_error("divide by zero");
         }
-#ifdef CHAISCRIPT_MSVC
-#pragma warning(pop)
 #endif
-
       }
-#else
+
       template<typename T>
-      static void check_divide_by_zero(T)
+      static void check_divide_by_zero(T, typename std::enable_if<std::is_floating_point<T>::value>::type* = 0)
       {
       }
-#endif
 
       struct boolean
       {
diff --git a/unittests/future.chai b/unittests/future.chai
index afb9afe..750c27d 100644
--- a/unittests/future.chai
+++ b/unittests/future.chai
@@ -1,6 +1,6 @@
 var func = fun(){
   var ret = 0;
-  for (var i = 0; i < 1000000; ++i) {
+  for (var i = 0; i < 50000; ++i) {
     ret += i;
   }
   return ret;
@@ -9,9 +9,7 @@ var func = fun(){
 
 var fut1 := async(func);
 var fut2 := async(func);
-var fut3 := async(func);
-var fut4 := async(func);
 
 // simply executing without crashing is good enough for this test
 
-print(" ${fut1.get()} ${fut2.get()} ${fut3.get()} ${fut4.get()}")
+print(" ${fut1.get()} ${fut2.get()} ")