From 7c616db71a5f7b1568a46a0044dcb636b2bc7ee6 Mon Sep 17 00:00:00 2001
From: Andrej Mitrovic <andrej.mitrovich@gmail.com>
Date: Mon, 4 Feb 2013 22:06:20 +0100
Subject: [PATCH] Fixes Issue 8837 - BigInt needs better operator constraints.

---
 std/bigint.d | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/std/bigint.d b/std/bigint.d
index c98ee6e72..a0bfc638c 100644
--- a/std/bigint.d
+++ b/std/bigint.d
@@ -27,6 +27,7 @@ module std.bigint;
 
 private import std.internal.math.biguintcore;
 private import std.format : FormatSpec, FormatException;
+private import std.traits;
 
 /** A struct representing an arbitrary precision integer
  *
@@ -105,14 +106,14 @@ public:
     }
 
     ///
-    this(T: long) (T x)
+    this(T)(T x) if (isIntegral!T)
     {
         data = data.init; // @@@: Workaround for compiler bug
         opAssign(x);
     }
 
     ///
-    BigInt opAssign(T: long)(T x)
+    BigInt opAssign(T)(T x) if (isIntegral!T)
     {
         data = cast(ulong)((x < 0) ? -x : x);
         sign = (x < 0);
@@ -130,7 +131,7 @@ public:
     // BigInt op= integer
     BigInt opOpAssign(string op, T)(T y)
         if ((op=="+" || op=="-" || op=="*" || op=="/" || op=="%"
-          || op==">>" || op=="<<" || op=="^^") && is (T: long))
+          || op==">>" || op=="<<" || op=="^^") && isIntegral!T)
     {
         ulong u = cast(ulong)(y < 0 ? -y : y);
 
@@ -252,7 +253,7 @@ public:
     // BigInt op integer
     BigInt opBinary(string op, T)(T y)
         if ((op=="+" || op == "*" || op=="-" || op=="/"
-            || op==">>" || op=="<<" || op=="^^") && is (T: long))
+            || op==">>" || op=="<<" || op=="^^") && isIntegral!T)
     {
         BigInt r = this;
         return r.opOpAssign!(op)(y);
@@ -260,7 +261,7 @@ public:
 
     //
     int opBinary(string op, T : int)(T y)
-        if (op == "%")
+        if (op == "%" && isIntegral!T)
     {
         assert(y!=0);
         uint u = y < 0 ? -y : y;
@@ -272,14 +273,14 @@ public:
 
     // Commutative operators
     BigInt opBinaryRight(string op, T)(T y)
-        if ((op=="+" || op=="*") && !is(T: BigInt))
+        if ((op=="+" || op=="*") && isIntegral!T)
     {
         return opBinary!(op)(y);
     }
 
     //  BigInt = integer op BigInt
     BigInt opBinaryRight(string op, T)(T y)
-        if (op == "-" && is(T: long))
+        if (op == "-" && isIntegral!T)
     {
         ulong u = cast(ulong)(y < 0 ? -y : y);
         BigInt r;
@@ -294,7 +295,7 @@ public:
 
     //  integer = integer op BigInt
     T opBinaryRight(string op, T)(T x)
-        if ((op=="%" || op=="/") && is(T: long))
+        if ((op=="%" || op=="/") && isIntegral!T)
     {
         static if (op == "%")
         {
@@ -350,7 +351,7 @@ public:
     }
 
     ///
-    bool opEquals(T: long)(T y) const
+    bool opEquals(T)(T y) const if (isIntegral!T)
     {
         if (sign != (y<0))
             return 0;
@@ -358,7 +359,7 @@ public:
     }
 
     ///
-    int opCmp(T:long)(T y)
+    int opCmp(T)(T y) if (isIntegral!T)
     {
         if (sign != (y<0) )
             return sign ? -1 : 1;