uni20::basic_half_int< T > Class Template Reference

Signed value type that stores multiples of one half exactly. More...

#include <half_int.hpp>

Classes
struct	twice_tag
	Tag type used to construct directly from the doubled representation. More...

Public Types
using	value_type = T
	Underlying signed storage type.

Public Member Functions
constexpr	basic_half_int ()=default
	Construct the value zero.
constexpr	basic_half_int (T twice_value, twice_tag tag)
	Construct directly from the doubled representation.
template<std::integral U>
constexpr	basic_half_int (U value)
	Construct from an integral value.
template<std::floating_point U>
	basic_half_int (U value)
	Construct by rounding a floating-point value to the nearest half-integer.
template<std::signed_integral U>
	explicit (std::numeric_limits< T >::digits< std::numeric_limits< U >::digits) const expr basic_half_int(basic_half_int< U > other) noexcept(std::numeric_limits< T >::digits >=std::numeric_limits< U >::digits)
	Convert another half-integer without changing its value.
constexpr auto	is_integral () const -> bool
	Return whether the represented value is integral.
constexpr auto	operator++ () -> basic_half_int &
	Prefix increment by one.
constexpr auto	operator++ (int) -> basic_half_int
	Postfix increment by one.
constexpr auto	operator+= (basic_half_int other) -> basic_half_int &
	Add another half-integer value.
constexpr auto	operator-- () -> basic_half_int &
	Prefix decrement by one.
constexpr auto	operator-- (int) -> basic_half_int
	Postfix decrement by one.
constexpr auto	operator-= (basic_half_int other) -> basic_half_int &
	Subtract another half-integer value.
constexpr auto	operator<=> (basic_half_int const &other) const =default
	Compare two half-integer values.
constexpr auto	to_double () const -> double
	Convert to double.
constexpr auto	to_int () const -> T
	Convert to the underlying integral type.
constexpr auto	to_int_assert () const -> T
	Convert to the underlying integral type assuming exact integrality.
constexpr auto	twice () const -> T
	Return the doubled representation.

Static Public Member Functions
static auto	parse (std::string_view text) -> basic_half_int
	Parse a textual half-integer representation.

Detailed Description

template<std::signed_integral T>
class uni20::basic_half_int< T >

Signed value type that stores multiples of one half exactly.

Template Parameters

T	Signed integer storage type used for the doubled representation.

Member Typedef Documentation

value_type

template<std::signed_integral T>

using uni20::basic_half_int< T >::value_type = T

Underlying signed storage type.

Constructor & Destructor Documentation

basic_half_int() [1/4]

template<std::signed_integral T>

constexpr uni20::basic_half_int< T >::basic_half_int ( )

constexprdefault

Construct the value zero.

basic_half_int() [2/4]

template<std::signed_integral T>

template<std::integral U>

constexpr uni20::basic_half_int< T >::basic_half_int ( U  value )

inlineconstexpr

Construct from an integral value.

Parameters

value

Integral value to represent exactly.

basic_half_int() [3/4]

template<std::signed_integral T>

template<std::floating_point U>

uni20::basic_half_int< T >::basic_half_int ( U  value )

inlineexplicit

Construct by rounding a floating-point value to the nearest half-integer.

Parameters

value

Floating-point value to round.

basic_half_int() [4/4]

template<std::signed_integral T>

constexpr uni20::basic_half_int< T >::basic_half_int ( T  twice_value, twice_tag  tag  )

inlineconstexpr

Construct directly from the doubled representation.

Parameters

twice_value	Stored doubled value.
tag	Selects the direct doubled-value constructor.

Member Function Documentation

explicit()

template<std::signed_integral T>

template<std::signed_integral U>

uni20::basic_half_int< T >::explicit ( ) const

inlinenoexcept

Convert another half-integer without changing its value.

Conversion is implicit and non-throwing when T can represent every doubled value of U. Narrowing requires explicit construction and checks the doubled representation before converting it.

Exceptions

std::overflow_error

If the doubled value does not fit in T.

is_integral()

template<std::signed_integral T>

constexpr auto uni20::basic_half_int< T >::is_integral ( ) const -> bool

inlineconstexpr

Return whether the represented value is integral.

Returns

true if the value has no half-integer part.

operator++() [1/2]

template<std::signed_integral T>

constexpr auto uni20::basic_half_int< T >::operator++ ( ) -> basic_half_int&

inlineconstexpr

Prefix increment by one.

Returns

Reference to *this.

operator++() [2/2]

template<std::signed_integral T>

constexpr auto uni20::basic_half_int< T >::operator++ ( int  ) -> basic_half_int

inlineconstexpr

Postfix increment by one.

Returns

Previous value.

operator+=()

template<std::signed_integral T>

constexpr auto uni20::basic_half_int< T >::operator+= ( basic_half_int< T >  other ) -> basic_half_int&

inlineconstexpr

Add another half-integer value.

Parameters

other

Value to add.

Returns

Reference to *this.

operator--() [1/2]

template<std::signed_integral T>

constexpr auto uni20::basic_half_int< T >::operator-- ( ) -> basic_half_int&

inlineconstexpr

Prefix decrement by one.

Returns

Reference to *this.

operator--() [2/2]

template<std::signed_integral T>

constexpr auto uni20::basic_half_int< T >::operator-- ( int  ) -> basic_half_int

inlineconstexpr

Postfix decrement by one.

Returns

Previous value.

operator-=()

template<std::signed_integral T>

constexpr auto uni20::basic_half_int< T >::operator-= ( basic_half_int< T >  other ) -> basic_half_int&

inlineconstexpr

Subtract another half-integer value.

Parameters

other

Value to subtract.

Returns

Reference to *this.

operator<=>()

template<std::signed_integral T>

constexpr auto uni20::basic_half_int< T >::operator<=> ( basic_half_int< T > const &  other ) const

constexprdefault

Compare two half-integer values.

Parameters

other

Other value to compare.

Returns

Ordering result based on the doubled representation.

parse()

template<std::signed_integral T>

static auto uni20::basic_half_int< T >::parse ( std::string_view  text ) -> basic_half_int

inlinestatic

Parse a textual half-integer representation.

Parameters

text	String form such as "3", "5/2", or "1.5".

Returns

Parsed half-integer value.

to_double()

template<std::signed_integral T>

constexpr auto uni20::basic_half_int< T >::to_double ( ) const -> double

inlineconstexpr

Convert to double.

Returns

Floating-point representation.

to_int()

template<std::signed_integral T>

constexpr auto uni20::basic_half_int< T >::to_int ( ) const -> T

inlineconstexpr

Convert to the underlying integral type.

Returns

Integral representation.

Exceptions

std::runtime_error

If the value is not integral.

to_int_assert()

template<std::signed_integral T>

constexpr auto uni20::basic_half_int< T >::to_int_assert ( ) const -> T

inlineconstexpr

Convert to the underlying integral type assuming exact integrality.

Returns

Integral representation.

Precondition

is_integral()

twice()

template<std::signed_integral T>

constexpr auto uni20::basic_half_int< T >::twice ( ) const -> T

inlineconstexpr

Return the doubled representation.

Returns

Stored doubled value.

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

• half_int.hpp