From 7b7c9ec3558ae51bb4fc3c1a499ddf988cee0086 Mon Sep 17 00:00:00 2001
From: Marshall Clow <mclow.lists@gmail.com>
Date: Mon, 16 Nov 2015 16:42:16 +0000
Subject: [PATCH] LWG#2156 loosened the requirements on unordered containers
 'rehash' calls. Add tests to make sure we meet these requirements. Since we
 met the stricter ones, no code change needed to meet the looser ones.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@253223 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/std/containers/unord/unord.map/rehash.pass.cpp  | 12 ++++++++++++
 .../containers/unord/unord.multimap/rehash.pass.cpp  | 12 ++++++++++++
 .../containers/unord/unord.multiset/rehash.pass.cpp  | 12 ++++++++++++
 test/std/containers/unord/unord.set/rehash.pass.cpp  | 12 ++++++++++++
 www/cxx1z_status.html                                |  2 +-
 5 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/test/std/containers/unord/unord.map/rehash.pass.cpp b/test/std/containers/unord/unord.map/rehash.pass.cpp
index 84ece235..e1a882c6 100644
--- a/test/std/containers/unord/unord.map/rehash.pass.cpp
+++ b/test/std/containers/unord/unord.map/rehash.pass.cpp
@@ -21,6 +21,12 @@
 
 #include "min_allocator.h"
 
+template <class C>
+void rehash_postcondition(const C& c, size_t n)
+{
+	assert(c.bucket_count() >= c.size() / c.max_load_factor() && c.bucket_count() >= n);
+}
+
 template <class C>
 void test(const C& c)
 {
@@ -49,13 +55,16 @@ int main()
         test(c);
         assert(c.bucket_count() >= 5);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 5);
         test(c);
         c.max_load_factor(2);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 3);
         test(c);
         c.rehash(31);
+        rehash_postcondition(c, 31);
         assert(c.bucket_count() == 31);
         test(c);
     }
@@ -77,13 +86,16 @@ int main()
         test(c);
         assert(c.bucket_count() >= 5);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 5);
         test(c);
         c.max_load_factor(2);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 3);
         test(c);
         c.rehash(31);
+        rehash_postcondition(c, 31);
         assert(c.bucket_count() == 31);
         test(c);
     }
diff --git a/test/std/containers/unord/unord.multimap/rehash.pass.cpp b/test/std/containers/unord/unord.multimap/rehash.pass.cpp
index 1d992085..d36dc42e 100644
--- a/test/std/containers/unord/unord.multimap/rehash.pass.cpp
+++ b/test/std/containers/unord/unord.multimap/rehash.pass.cpp
@@ -22,6 +22,12 @@
 
 #include "min_allocator.h"
 
+template <class C>
+void rehash_postcondition(const C& c, size_t n)
+{
+	assert(c.bucket_count() >= c.size() / c.max_load_factor() && c.bucket_count() >= n);
+}
+
 template <class C>
 void test(const C& c)
 {
@@ -77,13 +83,16 @@ int main()
         test(c);
         assert(c.bucket_count() >= 7);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 7);
         test(c);
         c.max_load_factor(2);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 3);
         test(c);
         c.rehash(31);
+        rehash_postcondition(c, 31);
         assert(c.bucket_count() == 31);
         test(c);
     }
@@ -105,13 +114,16 @@ int main()
         test(c);
         assert(c.bucket_count() >= 7);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 7);
         test(c);
         c.max_load_factor(2);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 3);
         test(c);
         c.rehash(31);
+        rehash_postcondition(c, 31);
         assert(c.bucket_count() == 31);
         test(c);
     }
diff --git a/test/std/containers/unord/unord.multiset/rehash.pass.cpp b/test/std/containers/unord/unord.multiset/rehash.pass.cpp
index bc8d461c..5c7c6aa8 100644
--- a/test/std/containers/unord/unord.multiset/rehash.pass.cpp
+++ b/test/std/containers/unord/unord.multiset/rehash.pass.cpp
@@ -20,6 +20,12 @@
 
 #include "min_allocator.h"
 
+template <class C>
+void rehash_postcondition(const C& c, size_t n)
+{
+	assert(c.bucket_count() >= c.size() / c.max_load_factor() && c.bucket_count() >= n);
+}
+
 template <class C>
 void test(const C& c)
 {
@@ -48,13 +54,16 @@ int main()
         test(c);
         assert(c.bucket_count() >= 7);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 7);
         test(c);
         c.max_load_factor(2);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 3);
         test(c);
         c.rehash(31);
+        rehash_postcondition(c, 31);
         assert(c.bucket_count() == 31);
         test(c);
     }
@@ -76,13 +85,16 @@ int main()
         test(c);
         assert(c.bucket_count() >= 7);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 7);
         test(c);
         c.max_load_factor(2);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 3);
         test(c);
         c.rehash(31);
+        rehash_postcondition(c, 31);
         assert(c.bucket_count() == 31);
         test(c);
     }
diff --git a/test/std/containers/unord/unord.set/rehash.pass.cpp b/test/std/containers/unord/unord.set/rehash.pass.cpp
index 30fffa56..e28c25dc 100644
--- a/test/std/containers/unord/unord.set/rehash.pass.cpp
+++ b/test/std/containers/unord/unord.set/rehash.pass.cpp
@@ -20,6 +20,12 @@
 
 #include "min_allocator.h"
 
+template <class C>
+void rehash_postcondition(const C& c, size_t n)
+{
+	assert(c.bucket_count() >= c.size() / c.max_load_factor() && c.bucket_count() >= n);
+}
+
 template <class C>
 void test(const C& c)
 {
@@ -48,13 +54,16 @@ int main()
         test(c);
         assert(c.bucket_count() >= 5);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 5);
         test(c);
         c.max_load_factor(2);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 3);
         test(c);
         c.rehash(31);
+        rehash_postcondition(c, 31);
         assert(c.bucket_count() == 31);
         test(c);
     }
@@ -76,13 +85,16 @@ int main()
         test(c);
         assert(c.bucket_count() >= 5);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 5);
         test(c);
         c.max_load_factor(2);
         c.rehash(3);
+        rehash_postcondition(c, 3);
         assert(c.bucket_count() == 3);
         test(c);
         c.rehash(31);
+        rehash_postcondition(c, 31);
         assert(c.bucket_count() == 31);
         test(c);
     }
diff --git a/www/cxx1z_status.html b/www/cxx1z_status.html
index 7d8238f3..67a334f5 100644
--- a/www/cxx1z_status.html
+++ b/www/cxx1z_status.html
@@ -154,7 +154,7 @@
 	<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2119">2119</a></td><td>Missing <tt>hash</tt> specializations for extended integer types</td><td>Kona</td><td></td></tr>
 	<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2127">2127</a></td><td>Move-construction with <tt>raw_storage_iterator</tt></td><td>Kona</td><td>Complete</td></tr>
 	<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2133">2133</a></td><td>Attitude to overloaded comma for iterators</td><td>Kona</td><td>Complete</td></tr>
-	<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2156">2156</a></td><td>Unordered containers' <tt>reserve(n)</tt> reserves for <tt>n-1</tt> elements</td><td>Kona</td><td></td></tr>
+	<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2156">2156</a></td><td>Unordered containers' <tt>reserve(n)</tt> reserves for <tt>n-1</tt> elements</td><td>Kona</td><td>Complete</td></tr>
 	<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2218">2218</a></td><td>Unclear how containers use <tt>allocator_traits::construct()</tt></td><td>Kona</td><td></td></tr>
 	<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2219">2219</a></td><td><tt><i>INVOKE</i></tt>-ing a pointer to member with a <tt>reference_wrapper</tt> as the object expression</td><td>Kona</td><td></td></tr>
 	<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2224">2224</a></td><td>Ambiguous status of access to non-live objects</td><td>Kona</td><td>Complete</td></tr>