ceph/src/boost/libs/math/doc/fp_utilities/rounding_func.qbk

   1
   2 [section:rounding Rounding Truncation and Integer Conversion]
   3
   4 [section:round Rounding Functions]
   5
   6 ``#include <boost/math/special_functions/round.hpp>``
   7
   8    template <class T>
   9    T round(const T& v);
  10
  11    template <class T, class Policy>
  12    T round(const T& v, const Policy&);
  13
  14    template <class T>
  15    int iround(const T& v);
  16
  17    template <class T, class Policy>
  18    int iround(const T& v, const Policy&);
  19
  20    template <class T>
  21    long lround(const T& v);
  22
  23    template <class T, class Policy>
  24    long lround(const T& v, const Policy&);
  25
  26    template <class T>
  27    long long llround(const T& v);
  28
  29    template <class T, class Policy>
  30    long long llround(const T& v, const Policy&);
  31
  32 These functions return the closest integer to the argument /v/.
  33
  34 Halfway cases are rounded away from zero, regardless of the current rounding
  35 direction.
  36
  37 If the argument /v/ is either non-finite or else outside the range
  38 of the result type, then returns the result of __rounding_error: by
  39 default this throws an instance of `boost::math::rounding_error`.
  40
  41 [endsect]
  42
  43 [section:trunc Truncation Functions]
  44
  45 ``#include <boost/math/special_functions/trunc.hpp>``
  46
  47    template <class T>
  48    T trunc(const T& v);
  49
  50    template <class T, class Policy>
  51    T trunc(const T& v, const Policy&);
  52
  53    template <class T>
  54    int itrunc(const T& v);
  55
  56    template <class T, class Policy>
  57    int itrunc(const T& v, const Policy&);
  58
  59    template <class T>
  60    long ltrunc(const T& v);
  61
  62    template <class T, class Policy>
  63    long ltrunc(const T& v, const Policy&);
  64
  65    template <class T>
  66    long long lltrunc(const T& v);
  67
  68    template <class T, class Policy>
  69    long long lltrunc(const T& v, const Policy&);
  70
  71 The trunc functions round their argument to the integer value,
  72 nearest to but no larger in magnitude than the argument.
  73
  74 For example `itrunc(3.7)` would return `3` and `ltrunc(-4.6)`
  75 would return `-4`.
  76
  77 If the argument /v/ is either non-finite or else outside the range
  78 of the result type, then returns the result of __rounding_error: by
  79 default this throws an instance of `boost::math::rounding_error`.
  80
  81 [endsect]
  82
  83 [section:modf Integer and Fractional Part Splitting (modf)]
  84
  85 ``#include <boost/math/special_functions/modf.hpp>``
  86
  87    template <class T>
  88    T modf(const T& v, T* ipart);
  89
  90    template <class T, class Policy>
  91    T modf(const T& v, T* ipart, const Policy&);
  92
  93    template <class T>
  94    T modf(const T& v, int* ipart);
  95
  96    template <class T, class Policy>
  97    T modf(const T& v, int* ipart, const Policy&);
  98
  99    template <class T>
 100    T modf(const T& v, long* ipart);
 101
 102    template <class T, class Policy>
 103    T modf(const T& v, long* ipart, const Policy&);
 104
 105    template <class T>
 106    T modf(const T& v, long long* ipart);
 107
 108    template <class T, class Policy>
 109    T modf(const T& v, long long* ipart, const Policy&);
 110
 111 The `modf` functions store the integer part of /v/ in `*ipart`
 112 and return the fractional part of /v/.  The sign of the integer
 113 and fractional parts are the same as the sign of /v/.
 114
 115 If the argument /v/ is either non-finite or else outside the range
 116 of the result type, then returns the result of __rounding_error: by
 117 default this throws an instance of `boost::math::rounding_error`.
 118
 119 [endsect]
 120
 121
 122 [endsect] [/section:rounding Rounding Truncation and Integer Conversion]
 123
 124 [/
 125   Copyright 2006 John Maddock and Paul A. Bristow.
 126   Distributed under the Boost Software License, Version 1.0.
 127   (See accompanying file LICENSE_1_0.txt or copy at
 128   http://www.boost.org/LICENSE_1_0.txt).
 129 ]