From 7e3f2cc6118ccc82570a57d33cd41730cb85b7d7 Mon Sep 17 00:00:00 2001
From: Johannes Loher <johannes.loher@fg4f.de>
Date: Thu, 9 Jun 2016 14:10:06 +0200
Subject: [PATCH] use static if for better readybility

---
 source/cipher.d  | 42 +++++++++++++++++++-----------------------
 source/salsa20.d |  2 +-
 2 files changed, 20 insertions(+), 24 deletions(-)

diff --git a/source/cipher.d b/source/cipher.d
index 96a73c4..d7195c3 100644
--- a/source/cipher.d
+++ b/source/cipher.d
@@ -14,8 +14,25 @@ enum Cipher
     chacha20
 }
 
-mixin(cipherFunctionString!(InputRange, isOnlyInputRange));
-mixin(cipherFunctionString!(ForwardRange, isForwardRange));
+template cipherFunction(R)
+if(isInputRange!R && is(ElementType!R : ubyte))
+{
+    static if(isForwardRange!R)
+        alias ReturnType = ForwardRange;
+    else
+        alias ReturnType = InputRange;
+
+    ReturnType!(ElementType!R) cipherFunction(R range, ubyte[32] key, ubyte[8] nonce, Cipher cipher)
+    {
+        final switch (cipher)
+        {
+            case Cipher.salsa20:
+                return range.salsa20Cipher(key, nonce).inputRangeObject;
+            case Cipher.chacha20:
+                return range.chacha20Cipher(key, nonce).inputRangeObject;
+        }
+    }
+}
 
 unittest
 {
@@ -31,24 +48,3 @@ unittest
     static assert(isForwardRange!(typeof(b)));
     static assert(isInputRange!(typeof(d)) && !(isForwardRange!(typeof(d))));
 }
-
-private:
-
-template isOnlyInputRange(R)
-{
-    enum isOnlyInputRange = isInputRange!R && !(isForwardRange!R);
-}
-
-enum cipherFunctionString(alias ReturnType, alias Constraint) = q{
-    %s!(ElementType!R) cipherFunction(R)(R range, ubyte[32] key, ubyte[8] nonce, Cipher cipher)
-        if (is(ElementType!R : ubyte) && %s!R)
-    {
-        final switch (cipher)
-        {
-            case Cipher.salsa20:
-                return range.salsa20Cipher(key, nonce).inputRangeObject;
-            case Cipher.chacha20:
-                return range.chacha20Cipher(key, nonce).inputRangeObject;
-        }
-    }
-}.format(__traits(identifier, ReturnType), __traits(identifier, Constraint));
diff --git a/source/salsa20.d b/source/salsa20.d
index 200adbf..b19d21d 100644
--- a/source/salsa20.d
+++ b/source/salsa20.d
@@ -91,7 +91,7 @@ unittest
 enum string rowRound(alias _x00, alias _x01, alias _x02, alias _x03,
                      alias _x04, alias _x05, alias _x06, alias _x07,
                      alias _x08, alias _x09, alias _x10, alias _x11,
-                     alias _x12, alias _x13, alias _x14, alias _x15,) = q{
+                     alias _x12, alias _x13, alias _x14, alias _x15) = q{
     mixin(quarterRound!(%1$s, %2$s, %3$s, %4$s));
     mixin(quarterRound!(%6$s, %7$s, %8$s, %5$s));
     mixin(quarterRound!(%11$s, %12$s, %9$s, %10$s));