CNL  2.0.2 (development)
Compositional Numeric Library
boost.multiprecision.h
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1 
2 // Copyright John McFarlane 2015 - 2016.
3 // Distributed under the Boost Software License, Version 1.0.
4 // (See accompanying file ../../LICENSE_1_0.txt or copy at
5 // http://www.boost.org/LICENSE_1_0.txt)
6 
9 
10 #if !defined(CNL_BOOST_MULTIPRECISION_H)
11 #define CNL_BOOST_MULTIPRECISION_H
12 
13 #include "../_impl/numbers/set_signedness.h"
14 #include "../_impl/numbers/signedness.h"
15 #include "../_impl/scaled/power.h"
16 #include "../constant.h"
17 #include "../num_traits.h"
18 #include "../rounding_integer.h"
19 
20 #include <boost/multiprecision/cpp_int.hpp>
21 
22 #include <type_traits>
23 
25 namespace cnl {
26  namespace _bmp = boost::multiprecision;
27 
30  // generic operators of boost::multiprecision::number
31 
32  namespace _impl {
33  template<typename T>
34  struct is_bmp_number : std::false_type {
35  };
36 
37  template<class Backend>
38  struct is_bmp_number<_bmp::number<Backend>> : std::true_type {
39  };
40  }
41 
42  template<class Backend>
43  struct is_integer<_bmp::number<Backend>> : std::true_type {
44  };
45 
46  template<
47  unsigned MinBits,
48  unsigned MaxBits,
49  _bmp::cpp_integer_type SignType,
50  _bmp::cpp_int_check_type Checked,
51  class Allocator>
52  struct is_integer<_bmp::cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator>>
53  : std::true_type {
54  };
55 
56  template<
57  int DestExponent, int SrcExponent, int Radix, unsigned NumBits,
58  _bmp::cpp_integer_type SignType>
59  struct custom_operator<
60  _impl::convert_op,
61  op_value<_bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, SignType>>, cnl::power<SrcExponent, Radix>>,
62  op_value<_bmp::cpp_int_backend<NumBits, NumBits, SignType>, cnl::power<DestExponent, Radix>>> {
63  [[nodiscard]] constexpr auto operator()(
64  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, SignType>> const& input) const
65  {
66  // when converting *from* scaled_integer
67  return input.backend();
68  }
69  };
70 
72  template<
73  int DestExponent, int SrcExponent, int Radix, unsigned NumBits,
74  _bmp::cpp_integer_type SignType, typename Input>
75  requires(!_impl::is_bmp_number<Input>::value) struct custom_operator<
76  _impl::convert_op,
77  op_value<Input, cnl::power<SrcExponent, Radix>>,
78  op_value<_bmp::cpp_int_backend<NumBits, NumBits, SignType>, cnl::power<DestExponent, Radix>>> {
79  [[nodiscard]] constexpr auto operator()(Input const& input) const
80  -> _bmp::cpp_int_backend<NumBits, NumBits, SignType>
81  {
82  return input;
83  }
84  };
86 
89  // type trait specializations of boost::multiprecision::number
90 
91  namespace _impl {
92  template<typename T>
93  struct is_boost_multiprecision : std::false_type {
94  };
95 
96  template<typename Backend>
97  struct is_boost_multiprecision<_bmp::number<Backend>> : std::true_type {
98  };
99  }
100 }
101 
103 namespace cnl::numbers {
104  template<unsigned NumBits>
105  struct signedness<_bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::signed_magnitude>>>
106  : std::true_type {
107  };
108 
109  template<unsigned NumBits>
110  struct signedness<
111  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::unsigned_magnitude>>>
112  : std::false_type {
113  };
114 
115  template<unsigned NumBits>
116  struct set_signedness<
117  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::signed_magnitude>>,
118  true> {
119  using type = _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::signed_magnitude>>;
120  };
121 
122  template<unsigned NumBits>
123  struct set_signedness<
124  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::unsigned_magnitude>>,
125  true> {
126  using type = _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::signed_magnitude>>;
127  };
128 
129  template<unsigned NumBits>
130  struct set_signedness<
131  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::signed_magnitude>>,
132  false> {
133  using type =
134  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::unsigned_magnitude>>;
135  };
136 
137  template<unsigned NumBits>
138  struct set_signedness<
139  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::unsigned_magnitude>>,
140  false> {
141  using type =
142  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::unsigned_magnitude>>;
143  };
144 }
145 
146 namespace cnl {
147  template<unsigned NumBits>
148  inline constexpr int
149  digits_v<_bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::signed_magnitude>>> = NumBits - 1;
150 
151  template<unsigned NumBits>
152  inline constexpr int
153  digits_v<_bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::unsigned_magnitude>>> = NumBits;
154 
155  template<unsigned NumBits, int MinNumDigits>
156  struct set_digits<
157  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::unsigned_magnitude>>,
158  MinNumDigits> {
159  using type = _bmp::number<
160  _bmp::cpp_int_backend<MinNumDigits, MinNumDigits, _bmp::unsigned_magnitude>>;
161  };
162 
163  template<unsigned NumBits, int MinNumDigits>
164  struct set_digits<
165  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::signed_magnitude>>,
166  MinNumDigits> {
167  using type = _bmp::number<
168  _bmp::cpp_int_backend<MinNumDigits + 1, MinNumDigits + 1, _bmp::signed_magnitude>>;
169  };
170 
171  template<unsigned NumBits>
172  struct to_rep<_bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::signed_magnitude>>> {
173  private:
174  using number_type =
175  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::signed_magnitude>>;
176 
177  public:
178  [[nodiscard]] constexpr auto& operator()(number_type& n) const
179  {
180  return n;
181  };
182 
183  [[nodiscard]] constexpr auto const& operator()(number_type const& n) const
184  {
185  return n;
186  };
187 
188  [[nodiscard]] constexpr auto operator()(number_type&& n) const
189  {
190  return n;
191  };
192  };
193 
194  template<unsigned NumBits>
195  struct to_rep<_bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::unsigned_magnitude>>> {
196  private:
197  using number_type =
198  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::unsigned_magnitude>>;
199 
200  public:
201  [[nodiscard]] constexpr auto& operator()(number_type& n) const
202  {
203  return n;
204  };
205 
206  [[nodiscard]] constexpr auto const& operator()(number_type const& n) const
207  {
208  return n;
209  };
210 
211  [[nodiscard]] constexpr auto operator()(number_type&& n) const
212  {
213  return std::move(n);
214  };
215  };
216 
218  template<unsigned NumBits, class Value>
219  requires(!_impl::is_boost_multiprecision<Value>::value) struct from_value<
220  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::signed_magnitude>>,
221  Value> {
222  private:
223  static constexpr auto _bits = digits_v<Value> + 1;
224 
225  public:
226  [[nodiscard]] constexpr auto operator()(Value const& value) const
227  -> _bmp::number<_bmp::cpp_int_backend<_bits, _bits, _bmp::signed_magnitude>>
228  {
229  return value;
230  }
231  };
232 
233  template<unsigned NumBits, class Value>
234  requires(!_impl::is_boost_multiprecision<Value>::value) struct from_value<
235  _bmp::number<_bmp::cpp_int_backend<NumBits, NumBits, _bmp::unsigned_magnitude>>,
236  Value> {
237  private:
238  static constexpr auto _bits = digits_v<Value>;
239 
240  public:
241  [[nodiscard]] constexpr auto operator()(Value const& value) const
242  -> _bmp::number<_bmp::cpp_int_backend<_bits, _bits, _bmp::unsigned_magnitude>>
243  {
244  return value;
245  }
246  };
248 
249  template<class LhsBackend, class RhsBackend>
250  struct from_value<_bmp::number<LhsBackend>, _bmp::number<RhsBackend>> {
251  [[nodiscard]] constexpr auto operator()(_bmp::number<RhsBackend> const& value) const
252  -> _bmp::number<RhsBackend>
253  {
254  return value;
255  }
256  };
257 
258  template<int Digits, int Radix, class Backend>
259  struct scale<Digits, Radix, _bmp::number<Backend>>
260  : _impl::default_scale<Digits, Radix, _bmp::number<Backend>> {
261  };
262 
263  template<class Backend>
264  struct rounding<_bmp::number<Backend>> : std::type_identity<native_rounding_tag> {
265  };
266 
267  template<class Backend>
268  struct rep_of<_bmp::number<Backend>> : std::type_identity<Backend> {
269  };
270 
273  // aliases of boost::multiprecision types
274 
275  namespace _sized_integer_impl {
276  template<unsigned NumBits, _bmp::cpp_integer_type SignType>
277  using backend = _bmp::cpp_int_backend<NumBits, NumBits, SignType>;
278 
279  template<unsigned NumBits, _bmp::cpp_integer_type SignType>
280  using number = _bmp::number<_sized_integer_impl::backend<NumBits, SignType>, _bmp::et_off>;
281  }
282 
288  template<unsigned NumDigits = digits_v<int>>
289  using signed_multiprecision =
290  _sized_integer_impl::number<NumDigits + 1, _bmp::signed_magnitude>;
291 
297  template<unsigned NumDigits = digits_v<unsigned>>
298  using unsigned_multiprecision =
299  _sized_integer_impl::number<NumDigits, _bmp::unsigned_magnitude>;
300 
306  template<unsigned NumDigits = digits_v<int>>
307  using multiprecision = signed_multiprecision<NumDigits>;
308 
311  // boost::multiprecision bitwise shift operators
312 
313  template<unsigned NumBits, CNL_IMPL_CONSTANT_VALUE_TYPE Value>
314  [[nodiscard]] constexpr auto operator<<(
315  _sized_integer_impl::number<NumBits, _bmp::signed_magnitude> const& lhs,
316  constant<Value>)
317  {
318  return lhs << Value;
319  }
320 
321  template<unsigned NumBits, CNL_IMPL_CONSTANT_VALUE_TYPE Value>
322  [[nodiscard]] constexpr auto operator<<(
323  _sized_integer_impl::number<NumBits, _bmp::unsigned_magnitude> const& lhs,
324  constant<Value>)
325  {
326  return lhs << Value;
327  }
328 
329  template<unsigned NumBits, CNL_IMPL_CONSTANT_VALUE_TYPE Value>
330  [[nodiscard]] constexpr auto operator>>(
331  _sized_integer_impl::number<NumBits, _bmp::unsigned_magnitude> const& lhs,
332  constant<Value>)
333  {
334  return lhs >> Value;
335  }
336 
337  template<unsigned NumBits, CNL_IMPL_CONSTANT_VALUE_TYPE Value>
338  [[nodiscard]] constexpr auto operator>>(
339  _sized_integer_impl::number<NumBits, _bmp::signed_magnitude> const& lhs,
340  constant<Value>)
341  {
342  return lhs >> Value;
343  }
344 }
345 
346 #endif // CNL_BOOST_MULTIPRECISION_H
std::false_type
std::move
T move(T... args)
cnl::multiprecision
signed_multiprecision< NumDigits > multiprecision
alias to a signed, fixed-size Boost.Multiprecision type suitable for specializing scaled_integer
Definition: boost.multiprecision.h:307
cnl::signed_multiprecision
_sized_integer_impl::number< NumDigits+1, _bmp::signed_magnitude > signed_multiprecision
alias to a signed, fixed-size Boost.Multiprecision type suitable for specializing scaled_integer
Definition: boost.multiprecision.h:290
cnl::unsigned_multiprecision
_sized_integer_impl::number< NumDigits, _bmp::unsigned_magnitude > unsigned_multiprecision
alias to an unsigned, fixed-size Boost.Multiprecision type suitable for specializing scaled_integer
Definition: boost.multiprecision.h:299
cnl
compositional numeric library
Definition: abort.h:15
cnl::constant
type whose value is also its non-type template parameter
Definition: constant.h:44
cnl::numbers
compositional numeric library, numbers header/namespace
Definition: numbers.h:16