ceph/src/boost/boost/container/detail/next_capacity.hpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2014-2015. Distributed under the Boost
   4 // Software License, Version 1.0. (See accompanying file
   5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // See http://www.boost.org/libs/container for documentation.
   8 //
   9 //////////////////////////////////////////////////////////////////////////////
  10 #ifndef BOOST_CONTAINER_DETAIL_NEXT_CAPACITY_HPP
  11 #define BOOST_CONTAINER_DETAIL_NEXT_CAPACITY_HPP
  12
  13 #ifndef BOOST_CONFIG_HPP
  14 #  include <boost/config.hpp>
  15 #endif
  16
  17 #if defined(BOOST_HAS_PRAGMA_ONCE)
  18 #  pragma once
  19 #endif
  20
  21 // container
  22 #include <boost/container/throw_exception.hpp>
  23 // container/detail
  24 #include <boost/container/detail/min_max.hpp>
  25
  26 #include <boost/static_assert.hpp>
  27
  28 namespace boost {
  29 namespace container {
  30 namespace dtl {
  31
  32 template<unsigned Minimum, unsigned Numerator, unsigned Denominator>
  33 struct grow_factor_ratio
  34 {
  35    BOOST_STATIC_ASSERT(Numerator > Denominator);
  36    BOOST_STATIC_ASSERT(Numerator   < 100);
  37    BOOST_STATIC_ASSERT(Denominator < 100);
  38    BOOST_STATIC_ASSERT(Denominator == 1 || (0 != Numerator % Denominator));
  39
  40    template<class SizeType>
  41    SizeType operator()(const SizeType cur_cap, const SizeType add_min_cap, const SizeType max_cap) const
  42    {
  43       const SizeType overflow_limit  = ((SizeType)-1) / Numerator;
  44
  45       SizeType new_cap = 0;
  46
  47       if(cur_cap <= overflow_limit){
  48          new_cap = cur_cap * Numerator / Denominator;
  49       }
  50       else if(Denominator == 1 || (SizeType(new_cap = cur_cap) / Denominator) > overflow_limit){
  51          new_cap = (SizeType)-1;
  52       }
  53       else{
  54          new_cap *= Numerator;
  55       }
  56       return max_value(SizeType(Minimum), max_value(cur_cap+add_min_cap, min_value(max_cap, new_cap)));
  57    }
  58 };
  59
  60 }  //namespace dtl {
  61
  62 struct growth_factor_50
  63    : dtl::grow_factor_ratio<0, 3, 2>
  64 {};
  65
  66 struct growth_factor_60
  67    : dtl::grow_factor_ratio<0, 8, 5>
  68 {};
  69
  70 struct growth_factor_100
  71    : dtl::grow_factor_ratio<0, 2, 1>
  72 {};
  73
  74 }  //namespace container {
  75 }  //namespace boost {
  76
  77 #endif   //#ifndef BOOST_CONTAINER_DETAIL_NEXT_CAPACITY_HPP