From 2b0969532ebf5c1850ead5f8260f2aa61616640d Mon Sep 17 00:00:00 2001
From: Jack Stouffer <jack@jackstouffer.com>
Date: Wed, 4 Jan 2017 15:20:49 -0500
Subject: [PATCH 1/2] micro-optimization in std.conv.parse

---
 std/conv.d | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/std/conv.d b/std/conv.d
index d7aec793e43..8d7fa8a1b71 100644
--- a/std/conv.d
+++ b/std/conv.d
@@ -2543,11 +2543,11 @@ Target parse(Target, Source)(ref Source p)
 
     enforce(!p.empty, bailOut());
 
-    char sign = 0;                       /* indicating +                 */
+    bool sign = false;
     switch (p.front)
     {
     case '-':
-        sign++;
+        sign = true;
         p.popFront();
         enforce(!p.empty, bailOut());
         if (toLower(p.front) == 'i')

From a30844663f3b829a201834844b1bf311bc1f6d09 Mon Sep 17 00:00:00 2001
From: Jack Stouffer <jack@jackstouffer.com>
Date: Thu, 5 Jan 2017 00:45:43 -0500
Subject: [PATCH 2/2] Removed auto-decoding from the floating point version of
 std.conv.parse

---
 std/conv.d | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/std/conv.d b/std/conv.d
index 8d7fa8a1b71..8d84bf6b2dc 100644
--- a/std/conv.d
+++ b/std/conv.d
@@ -2519,7 +2519,7 @@ Target parse(Target, Source)(ref Source s)
  *     A $(LREF ConvException) if `p` is empty, if no number could be
  *     parsed, or if an overflow occurred.
  */
-Target parse(Target, Source)(ref Source p)
+Target parse(Target, Source)(ref Source source)
     if (isInputRange!Source && isSomeChar!(ElementType!Source) && !is(Source == enum) &&
         isFloatingPoint!Target && !is(Target == enum))
 {
@@ -2527,6 +2527,16 @@ Target parse(Target, Source)(ref Source p)
     import std.exception : enforce;
     import core.stdc.math : HUGE_VAL;
 
+    static if (isNarrowString!Source)
+    {
+        import std.string : representation, assumeUTF;
+        auto p = source.representation;
+    }
+    else
+    {
+        alias p = source;
+    }
+
     static immutable real[14] negtab =
         [ 1e-4096L,1e-2048L,1e-1024L,1e-512L,1e-256L,1e-128L,1e-64L,1e-32L,
                 1e-16L,1e-8L,1e-4L,1e-2L,1e-1L,1.0L ];
@@ -2541,6 +2551,7 @@ Target parse(Target, Source)(ref Source p)
         return new ConvException(text(msg, " for input \"", p, "\"."), fn, ln);
     }
 
+
     enforce(!p.empty, bailOut());
 
     bool sign = false;
@@ -2569,6 +2580,8 @@ Target parse(Target, Source)(ref Source p)
             {
                 // 'inf'
                 p.popFront();
+                static if (isNarrowString!Source)
+                    source = p.assumeUTF;
                 return sign ? -Target.infinity : Target.infinity;
             }
         }
@@ -2583,7 +2596,9 @@ Target parse(Target, Source)(ref Source p)
         p.popFront();
         if (p.empty)
         {
-            return (sign) ? -0.0 : 0.0;
+            static if (isNarrowString!Source)
+                source = p.assumeUTF;
+            return sign ? -0.0 : 0.0;
         }
 
         isHex = p.front == 'x' || p.front == 'X';
@@ -2805,6 +2820,8 @@ Target parse(Target, Source)(ref Source p)
                    new ConvException("error converting input to floating point"));
             // skip past the last 'n'
             p.popFront();
+            static if (isNarrowString!Source)
+                source = p.assumeUTF;
             return typeof(return).nan;
         }
 
@@ -2917,7 +2934,9 @@ Target parse(Target, Source)(ref Source p)
     enforce(ldval != HUGE_VAL, new ConvException("Range error"));
 
   L1:
-    return (sign) ? -ldval : ldval;
+    static if (isNarrowString!Source)
+        source = p.assumeUTF;
+    return sign ? -ldval : ldval;
 }
 
 ///