sg14::fixed_point< Rep, Exponent > Class Template Reference

literal real number approximation that uses fixed-point arithmetic More...

#include <sg14/fixed_point>

Inherits sg14::_impl::number_base< fixed_point< Rep, Exponent >, Rep >.

Public Types
using	rep = Rep
	alias to template parameter, Rep

Public Member Functions
constexpr	fixed_point ()
	default constructor
template<class FromRep , int FromExponent>
constexpr	fixed_point (const fixed_point< FromRep, FromExponent > &rhs)
	constructor taking a fixed-point type
template<class Integral , Integral Constant>
constexpr	fixed_point (const std::integral_constant< Integral, Constant > &)
	constructor taking an integral_constant type
template<class S , _impl::enable_if_t< std::numeric_limits< S >::is_integer, int > Dummy = 0>
constexpr	fixed_point (const S &s)
	constructor taking an integer type
template<class Integral , Integral Value, int Digits>
constexpr	fixed_point (const_integer< Integral, Value, Digits, Exponent > ci)
	constructor taking an integral_constant type
template<class S , _impl::enable_if_t< std::numeric_limits< S >::is_iec559, int > Dummy = 0>
constexpr	fixed_point (S s)
	constructor taking a floating-point type
template<class S , _impl::enable_if_t< std::numeric_limits< S >::is_integer, int > Dummy = 0>
constexpr	operator S () const
	returns value represented as integral
template<class S , _impl::enable_if_t< std::numeric_limits< S >::is_iec559, int > Dummy = 0>
constexpr	operator S () const
	returns value represented as floating-point
template<typename R = Rep>
constexpr	operator typename std::enable_if< std::is_convertible< Rep, bool >::value, bool > () const
	returns value represented as bool
template<class S , _impl::enable_if_t< std::numeric_limits< S >::is_integer, int > Dummy = 0>
fixed_point &	operator= (S s)
	copy assignment operator taking an integer type
template<class S , _impl::enable_if_t< std::numeric_limits< S >::is_iec559, int > Dummy = 0>
fixed_point &	operator= (S s)
	copy assignment operator taking a floating-point type
template<class FromRep , int FromExponent>
fixed_point &	operator= (const fixed_point< FromRep, FromExponent > &rhs)
	copy assignement operator taking a fixed-point type

Static Public Member Functions
static constexpr fixed_point	from_data (rep const &r)
	creates an instance given the underlying representation value

Static Public Attributes
static constexpr int	digits = std::numeric_limits<Rep>::digits
	number of binary digits this type can represent; equivalent to std::numeric_limits::digits
static constexpr int	exponent = Exponent
	value of template parameter, Exponent
static constexpr int	fractional_digits = -exponent
	number of binary digits devoted to fractional part of value; can be negative for specializations with especially large ranges
static constexpr int	integer_digits = digits+exponent
	number of binary digits devoted to integer part of value; can be negative for specializations with especially small ranges

Detailed Description

template<class Rep, int Exponent>
class sg14::fixed_point< Rep, Exponent >

literal real number approximation that uses fixed-point arithmetic

Template Parameters

Rep	the underlying type used to represent the value
Exponent	the value by which to scale the integer value in order to get the real value

Examples

To define a fixed-point value 1 byte in size with a sign bit, 3 integer bits and 4 fractional bits:

constexpr auto n = fixed_point<char, -3>{-2.75};
static_assert(n==-2.75, "fixed-point type was unable to store the value");