From 527a72860de579a505d955087f87b0510a98b66c Mon Sep 17 00:00:00 2001
From: Daniel James <daniel@calamity.org.uk>
Date: Mon, 24 Nov 2008 22:55:14 +0000
Subject: [PATCH] Extra tests for equality with different hash functions.

[SVN r49924]
---
 test/unordered/equality_tests.cpp | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/test/unordered/equality_tests.cpp b/test/unordered/equality_tests.cpp
index ff0e6b57..997e609d 100644
--- a/test/unordered/equality_tests.cpp
+++ b/test/unordered/equality_tests.cpp
@@ -13,6 +13,10 @@ namespace equality_tests
 {
     struct mod_compare
     {
+        bool alt_hash_;
+
+        explicit mod_compare(bool alt_hash = false) : alt_hash_(alt_hash) {}
+
         bool operator()(int x, int y) const
         {
             return x % 1000 == y % 1000;
@@ -20,7 +24,7 @@ namespace equality_tests
 
         int operator()(int x) const
         {
-            return x % 250;
+            return alt_hash_ ? x % 250 : (x + 5) % 250;
         }
     };
 
@@ -138,6 +142,25 @@ namespace equality_tests
             ((1)(2))((1001)(1)), ==, ((1001)(2))((1)(1)));
     }
 
+    // Test that equality still works when the two containers have
+    // different hash functions but the same equality predicate.
+
+    UNORDERED_AUTO_TEST(equality_different_hash_test)
+    {
+        typedef boost::unordered_set<int, mod_compare, mod_compare> set;
+        set set1(0, mod_compare(false), mod_compare(false));
+        set set2(0, mod_compare(true), mod_compare(true));
+        BOOST_CHECK(set1 == set2);
+        set1.insert(1); set2.insert(2);
+        BOOST_CHECK(set1 != set2);
+        set1.insert(2); set2.insert(1);
+        BOOST_CHECK(set1 == set2);
+        set1.insert(10); set2.insert(20);
+        BOOST_CHECK(set1 != set2);
+        set1.insert(20); set2.insert(10);
+        BOOST_CHECK(set1 == set2);
+    }
+
 }
 
 RUN_TESTS()