From 5b9b2c26dc1acaff86c8724ad756fbba4350d89a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ion=20Gazta=C3=B1aga?= <igaztanaga@gmail.com>
Date: Sun, 29 Sep 2013 11:36:06 +0000
Subject: [PATCH] Implemented 2x grow factor for vector capacity

[SVN r85996]
---
 include/boost/container/detail/utilities.hpp | 24 ++++++++++++--------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/include/boost/container/detail/utilities.hpp b/include/boost/container/detail/utilities.hpp
index c42087c..8aa020a 100644
--- a/include/boost/container/detail/utilities.hpp
+++ b/include/boost/container/detail/utilities.hpp
@@ -24,6 +24,7 @@
 #include <boost/move/core.hpp>
 #include <boost/move/utility.hpp>
 #include <boost/move/iterator.hpp>
+#include <boost/container/throw_exception.hpp>
 #include <boost/container/detail/mpl.hpp>
 #include <boost/container/detail/type_traits.hpp>
 #include <boost/container/allocator_traits.hpp>
@@ -115,18 +116,21 @@ SizeType
                     ,const SizeType capacity
                     ,const SizeType n)
 {
-//   if (n > max_size - capacity)
-//      throw std::length_error("get_next_capacity");
+   const SizeType remaining = max_size - capacity;
+   if ( remaining < n )
+      boost::container::throw_length_error("get_next_capacity, allocator's max_size reached");
+   const SizeType additional = max_value(n, capacity);
+   return ( remaining < additional ) ? max_size : ( capacity + additional );
+   #if 0 //Alternative for 50% grow
+      const SizeType m3 = max_size/3;
 
-   const SizeType m3 = max_size/3;
+      if (capacity < m3)
+         return capacity + max_value(3*(capacity+1)/5, n);
 
-   if (capacity < m3)
-      return capacity + max_value(3*(capacity+1)/5, n);
-
-   if (capacity < m3*2)
-      return capacity + max_value((capacity+1)/2, n);
-
-   return max_size;
+      if (capacity < m3*2)
+         return capacity + max_value((capacity+1)/2, n);
+      return max_size;
+   #endif
 }
 
 template <class T>