vnix::rat::encoding< NMR_BITS, DNM_BITS > Class Template Reference

Encoding of numerator and denominator into unsigned word. More...

#include <encoding.hpp>

Inheritance diagram for vnix::rat::encoding< NMR_BITS, DNM_BITS >:

Collaboration diagram for vnix::rat::encoding< NMR_BITS, DNM_BITS >:

Public Types
enum	{ BITS = NMR_BITS + DNM_BITS }
enum	{ DNM_MASK = bit_range<utype>(0, DNM_BITS - 1), NMR_MASK = bit_range<utype>(DNM_BITS, BITS - 1) }
	Mask for each of numerator and denominator. More...
using	utype = typename int_types< BITS >::US
	Unsigned type for encoding. More...
using	stype = typename int_types< BITS >::SS
	Signed type for encoding. More...
using	uftype = typename int_types< BITS >::UF
	Unsigned fast type. More...
using	sftype = typename int_types< BITS >::SF
	Signed fast type. More...

Public Member Functions
constexpr	encoding (normalized_pair< NMR_BITS, DNM_BITS > p)
	Initialize from normalized numerator and denominator. More...
constexpr int_types< NMR_BITS >::SF	n () const
	Normalized numerator. More...
constexpr int_types< DNM_BITS >::UF	d () const
	Normalized denominator. More...

Protected Member Functions
constexpr	encoding (utype c)
	Allow descendant to construct from code-word. More...

Protected Attributes
utype	c_
	Unsigned word storing encoding. More...

Static Private Member Functions
static constexpr utype	encode (normalized_pair< NMR_BITS, DNM_BITS > p)
	Calculated encoding from normalized numerator and denominator. More...

Detailed Description

template<unsigned NMR_BITS, unsigned DNM_BITS>
class vnix::rat::encoding< NMR_BITS, DNM_BITS >

Encoding of numerator and denominator into unsigned word.

Template Parameters

NMR_BITS	Number of bits for numerator.
DNM_BITS	Number of bits for denominator.

Definition at line 19 of file encoding.hpp.

Member Typedef Documentation

template<unsigned NMR_BITS, unsigned DNM_BITS>

using vnix::rat::encoding< NMR_BITS, DNM_BITS >::sftype = typename int_types<BITS>::SF

Signed fast type.

Definition at line 25 of file encoding.hpp.

template<unsigned NMR_BITS, unsigned DNM_BITS>

using vnix::rat::encoding< NMR_BITS, DNM_BITS >::stype = typename int_types<BITS>::SS

Signed type for encoding.

Definition at line 23 of file encoding.hpp.

template<unsigned NMR_BITS, unsigned DNM_BITS>

using vnix::rat::encoding< NMR_BITS, DNM_BITS >::uftype = typename int_types<BITS>::UF

Unsigned fast type.

Definition at line 24 of file encoding.hpp.

template<unsigned NMR_BITS, unsigned DNM_BITS>

using vnix::rat::encoding< NMR_BITS, DNM_BITS >::utype = typename int_types<BITS>::US

Unsigned type for encoding.

Definition at line 22 of file encoding.hpp.

Member Enumeration Documentation

template<unsigned NMR_BITS, unsigned DNM_BITS>

anonymous enum

Enumerator
BITS	Total number of bits.

Definition at line 21 of file encoding.hpp.

{  BITS = NMR_BITS + DNM_BITS };

template<unsigned NMR_BITS, unsigned DNM_BITS>

anonymous enum

Mask for each of numerator and denominator.

Enumerator
DNM_MASK	Mask for denominator.
NMR_MASK	Mask for numerator.

Definition at line 28 of file encoding.hpp.

       {
    DNM_MASK = bit_range<utype>(0, DNM_BITS - 1),   
    NMR_MASK = bit_range<utype>(DNM_BITS, BITS - 1) 
  };

Constructor & Destructor Documentation

template<unsigned NMR_BITS, unsigned DNM_BITS>

constexpr vnix::rat::encoding< NMR_BITS, DNM_BITS >::encoding ( utype  c )

inlineprotected

Allow descendant to construct from code-word.

Parameters

c	Code-word.

Definition at line 47 of file encoding.hpp.

: c_(c) {}

template<unsigned NMR_BITS, unsigned DNM_BITS>

constexpr vnix::rat::encoding< NMR_BITS, DNM_BITS >::encoding ( normalized_pair< NMR_BITS, DNM_BITS >  p )

inline

Initialize from normalized numerator and denominator.

Parameters

p	Normalized numerator and denominator.

Definition at line 52 of file encoding.hpp.

: c_(encode(p)) {}

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Member Function Documentation

template<unsigned NMR_BITS, unsigned DNM_BITS>

constexpr int_types<DNM_BITS>::UF vnix::rat::encoding< NMR_BITS, DNM_BITS >::d ( ) const

inline

Normalized denominator.

Definition at line 68 of file encoding.hpp.

                                                     {
    return (c_ & DNM_MASK) + 1;
  }

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template<unsigned NMR_BITS, unsigned DNM_BITS>

static constexpr utype vnix::rat::encoding< NMR_BITS, DNM_BITS >::encode ( normalized_pair< NMR_BITS, DNM_BITS >  p )

inlinestaticprivate

Calculated encoding from normalized numerator and denominator.

Parameters

p	Normalized numerator and denominator.

Definition at line 36 of file encoding.hpp.

                                                                       {
    utype const num_enc = utype(p.n()) << DNM_BITS;
    utype const den_enc = (p.d() - 1) & DNM_MASK;
    return num_enc | den_enc;
  }

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template<unsigned NMR_BITS, unsigned DNM_BITS>

constexpr int_types<NMR_BITS>::SF vnix::rat::encoding< NMR_BITS, DNM_BITS >::n ( ) const

inline

Normalized numerator.

Definition at line 55 of file encoding.hpp.

                                                     {
    // Perform arithmetic right-shift on signed number.  With C++20, this could
    // be done simply as 'return stype(c_) >> DNM_BITS'.
    uftype const sign_bit = c_ & bit<uftype>(BITS - 1);
    uftype const shifted  = c_ >> DNM_BITS;
    enum { UFTYPE_BITS = 8 * sizeof(uftype) };
    if (sign_bit && NMR_BITS < UFTYPE_BITS) {
      return sftype(shifted | bit_range<uftype>(NMR_BITS, UFTYPE_BITS - 1));
    }
    return sftype(shifted);
  }

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Member Data Documentation

template<unsigned NMR_BITS, unsigned DNM_BITS>

utype vnix::rat::encoding< NMR_BITS, DNM_BITS >::c_

protected

Unsigned word storing encoding.

Definition at line 43 of file encoding.hpp.

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The documentation for this class was generated from the following file:

• vnix/rat/encoding.hpp