From c2e7221bf9c93643b6e16c2c605ad365ba69020e Mon Sep 17 00:00:00 2001
From: Daniel James <daniel@calamity.org.uk>
Date: Mon, 17 Sep 2012 18:57:58 +0000
Subject: [PATCH] Unordered: Set `max_load_` to 0 when there are no buckets.

[SVN r80559]
---
 include/boost/unordered/detail/table.hpp  | 17 ++++++++++-------
 include/boost/unordered/detail/unique.hpp | 22 +++-------------------
 2 files changed, 13 insertions(+), 26 deletions(-)

diff --git a/include/boost/unordered/detail/table.hpp b/include/boost/unordered/detail/table.hpp
index 70a46572..5ce391d6 100644
--- a/include/boost/unordered/detail/table.hpp
+++ b/include/boost/unordered/detail/table.hpp
@@ -187,7 +187,7 @@ namespace boost { namespace unordered { namespace detail {
         std::size_t bucket_count_;
         std::size_t size_;
         float mlf_;
-        std::size_t max_load_; // Only use if buckets_.
+        std::size_t max_load_;
         bucket_pointer buckets_;
 
         ////////////////////////////////////////////////////////////////////////
@@ -292,10 +292,10 @@ namespace boost { namespace unordered { namespace detail {
     
             // From 6.3.1/13:
             // Only resize when size >= mlf_ * count
-            max_load_ = boost::unordered::detail::double_to_size(ceil(
+            max_load_ = buckets_ ? boost::unordered::detail::double_to_size(ceil(
                     static_cast<double>(mlf_) *
                     static_cast<double>(bucket_count_)
-                ));
+                )) : 0;
 
         }
 
@@ -303,7 +303,7 @@ namespace boost { namespace unordered { namespace detail {
         {
             BOOST_ASSERT(z > 0);
             mlf_ = (std::max)(z, minimum_max_load_factor);
-            if (buckets_) recalculate_max_load();
+            recalculate_max_load();
         }
 
         std::size_t min_buckets_for_size(std::size_t size) const
@@ -362,6 +362,7 @@ namespace boost { namespace unordered { namespace detail {
         {
             x.buckets_ = bucket_pointer();
             x.size_ = 0;
+            x.max_load_ = 0;
         }
 
         table(table& x, node_allocator const& a,
@@ -487,6 +488,7 @@ namespace boost { namespace unordered { namespace detail {
             size_ = other.size_;
             other.buckets_ = bucket_pointer();
             other.size_ = 0;
+            other.max_load_ = 0;
         }
 
         ////////////////////////////////////////////////////////////////////////
@@ -536,6 +538,7 @@ namespace boost { namespace unordered { namespace detail {
 
                 destroy_buckets();
                 buckets_ = bucket_pointer();
+                max_load_ = 0;
             }
 
             BOOST_ASSERT(!size_);
@@ -680,7 +683,7 @@ namespace boost { namespace unordered { namespace detail {
 
             if (!size_ && !x.size_) return;
 
-            if (!buckets_ || x.size_ >= max_load_) {
+            if (x.size_ >= max_load_) {
                 create_buckets(min_buckets_for_size(x.size_));
             }
             else {
@@ -760,7 +763,7 @@ namespace boost { namespace unordered { namespace detail {
 
                 if (!size_ && !x.size_) return;
 
-                if (!buckets_ || x.size_ >= max_load_) {
+                if (x.size_ >= max_load_) {
                     create_buckets(min_buckets_for_size(x.size_));
                 }
                 else {
@@ -784,9 +787,9 @@ namespace boost { namespace unordered { namespace detail {
             boost::unordered::detail::set_hash_functions<hasher, key_equal>
                 new_func_this(*this, x);
             // No throw from here.
-            move_buckets_from(x);
             mlf_ = x.mlf_;
             max_load_ = x.max_load_;
+            move_buckets_from(x);
             new_func_this.commit();
         }
 
diff --git a/include/boost/unordered/detail/unique.hpp b/include/boost/unordered/detail/unique.hpp
index bd3c63cd..59e44663 100644
--- a/include/boost/unordered/detail/unique.hpp
+++ b/include/boost/unordered/detail/unique.hpp
@@ -466,14 +466,9 @@ namespace boost { namespace unordered { namespace detail {
         {
             node_constructor a(this->node_alloc());
 
-            // Special case for empty buckets so that we can use
-            // max_load_ (which isn't valid when buckets_ is null).
-            if (!this->buckets_) {
-                insert_range_empty(a, k, i, j);
-                if (++i == j) return;
-            }
+            insert_range_impl2(a, k, i, j);
 
-            do {
+            while(++i != j) {
                 // Note: can't use get_key as '*i' might not be value_type - it
                 // could be a pair with first_types as key_type without const or
                 // a different second_type.
@@ -483,18 +478,7 @@ namespace boost { namespace unordered { namespace detail {
                 // be less efficient if copying the full value_type is
                 // expensive.
                 insert_range_impl2(a, extractor::extract(*i), i, j);
-            } while(++i != j);
-        }
-
-        template <class InputIt>
-        void insert_range_empty(node_constructor& a, key_type const& k,
-            InputIt i, InputIt j)
-        {
-            std::size_t key_hash = this->hash(k);
-            a.construct_with_value2(*i);
-            this->reserve_for_insert(this->size_ +
-                boost::unordered::detail::insert_size(i, j));
-            this->add_node(a, key_hash);
+            }
         }
 
         template <class InputIt>