/usr/include/boost/geometry/util/select_most_precise.hpp is in libboost1.55-dev 1.55.0+dfsg-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 | // Boost.Geometry (aka GGL, Generic Geometry Library)
// Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
// Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
// Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
// Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
// (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
// Use, modification and distribution is subject to the Boost Software License,
// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_GEOMETRY_UTIL_SELECT_MOST_PRECISE_HPP
#define BOOST_GEOMETRY_UTIL_SELECT_MOST_PRECISE_HPP
#include <boost/mpl/if.hpp>
#include <boost/type_traits.hpp>
namespace boost { namespace geometry
{
#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace select_most_precise
{
// At least one of the types is non-fundamental. Take that one.
// if both are non-fundamental, the type-to-be-selected
// is unknown, it should be defined by explicit specialization.
template <bool Fundamental1, bool Fundamental2, typename T1, typename T2>
struct select_non_fundamental
{
typedef T1 type;
};
template <typename T1, typename T2>
struct select_non_fundamental<true, false, T1, T2>
{
typedef T2 type;
};
template <typename T1, typename T2>
struct select_non_fundamental<false, true, T1, T2>
{
typedef T1 type;
};
// Selection of largest type (e.g. int of <short int,int>
// It defaults takes the first one, if second is larger, take the second one
template <bool SecondLarger, typename T1, typename T2>
struct select_largest
{
typedef T1 type;
};
template <typename T1, typename T2>
struct select_largest<true, T1, T2>
{
typedef T2 type;
};
// Selection of floating point and specializations:
// both FP or both !FP does never occur...
template <bool FP1, bool FP2, typename T1, typename T2>
struct select_floating_point
{
typedef char type;
};
// ... so if ONE but not both of these types is floating point, take that one
template <typename T1, typename T2>
struct select_floating_point<true, false, T1, T2>
{
typedef T1 type;
};
template <typename T1, typename T2>
struct select_floating_point<false, true, T1, T2>
{
typedef T2 type;
};
}} // namespace detail::select_most_precise
#endif // DOXYGEN_NO_DETAIL
/*!
\brief Meta-function to select, of two types, the most accurate type for
calculations
\ingroup utility
\details select_most_precise classes, compares two types on compile time.
For example, if an addition must be done with a double and an integer, the
result must be a double.
If both types are integer, the result can be an integer.
\note It is different from the "promote" class, already in boost. That
class promotes e.g. a (one) float to a double. This class selects a
type from two types. It takes the most accurate, but does not promote
afterwards.
\note This traits class is completely independant from GGL and might be a
separate addition to Boost
\note If the input is a non-fundamental type, it might be a calculation
type such as a GMP-value or another high precision value. Therefore,
if one is non-fundamental, that one is chosen.
\note If both types are non-fundamental, the result is indeterminate and
currently the first one is chosen.
*/
template <typename T1, typename T2>
struct select_most_precise
{
static const bool second_larger = sizeof(T2) > sizeof(T1);
static const bool one_not_fundamental = !
(boost::is_fundamental<T1>::type::value
&& boost::is_fundamental<T2>::type::value);
static const bool both_same =
boost::is_floating_point<T1>::type::value
== boost::is_floating_point<T2>::type::value;
typedef typename boost::mpl::if_c
<
one_not_fundamental,
typename detail::select_most_precise::select_non_fundamental
<
boost::is_fundamental<T1>::type::value,
boost::is_fundamental<T2>::type::value,
T1,
T2
>::type,
typename boost::mpl::if_c
<
both_same,
typename detail::select_most_precise::select_largest
<
second_larger,
T1,
T2
>::type,
typename detail::select_most_precise::select_floating_point
<
boost::is_floating_point<T1>::type::value,
boost::is_floating_point<T2>::type::value,
T1,
T2
>::type
>::type
>::type type;
};
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_UTIL_SELECT_MOST_PRECISE_HPP
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