half_float::half Class Reference

Half-precision floating point type. More...

Collaboration diagram for half_float::half:

Public Member Functions
	half ()
	Default constructor. More...
	half (detail::expr rhs)
	Copy constructor. More...
	half (float rhs)
	Conversion constructor. More...
	operator float () const
	Conversion to single-precision. More...
half &	operator= (detail::expr rhs)
	Assignment operator. More...
template<typename T >
detail::enable< half &, T >::type	operator+= (T rhs)
	Arithmetic assignment. More...
template<typename T >
detail::enable< half &, T >::type	operator-= (T rhs)
	Arithmetic assignment. More...
template<typename T >
detail::enable< half &, T >::type	operator*= (T rhs)
	Arithmetic assignment. More...
template<typename T >
detail::enable< half &, T >::type	operator/= (T rhs)
	Arithmetic assignment. More...
half &	operator= (float rhs)
	Assignment operator. More...
half &	operator+= (float rhs)
	Arithmetic assignment. More...
half &	operator-= (float rhs)
	Arithmetic assignment. More...
half &	operator*= (float rhs)
	Arithmetic assignment. More...
half &	operator/= (float rhs)
	Arithmetic assignment. More...
half &	operator++ ()
	Prefix increment. More...
half &	operator-- ()
	Prefix decrement. More...
half	operator++ (int)
	Postfix increment. More...
half	operator-- (int)
	Postfix decrement. More...
	half ()
	Default constructor. More...
	half (detail::expr rhs)
	Copy constructor. More...
	half (float rhs)
	Conversion constructor. More...
	operator float () const
	Conversion to single-precision. More...
half &	operator= (detail::expr rhs)
	Assignment operator. More...
template<typename T >
detail::enable< half &, T >::type	operator+= (T rhs)
	Arithmetic assignment. More...
template<typename T >
detail::enable< half &, T >::type	operator-= (T rhs)
	Arithmetic assignment. More...
template<typename T >
detail::enable< half &, T >::type	operator*= (T rhs)
	Arithmetic assignment. More...
template<typename T >
detail::enable< half &, T >::type	operator/= (T rhs)
	Arithmetic assignment. More...
half &	operator= (float rhs)
	Assignment operator. More...
half &	operator+= (float rhs)
	Arithmetic assignment. More...
half &	operator-= (float rhs)
	Arithmetic assignment. More...
half &	operator*= (float rhs)
	Arithmetic assignment. More...
half &	operator/= (float rhs)
	Arithmetic assignment. More...
half &	operator++ ()
	Prefix increment. More...
half &	operator-- ()
	Prefix decrement. More...
half	operator++ (int)
	Postfix increment. More...
half	operator-- (int)
	Postfix decrement. More...

Private Member Functions
	half (detail::binary_t, detail::uint16 bits)
	Constructor. More...
	half (detail::binary_t, detail::uint16 bits)
	Constructor. More...

Private Attributes
detail::uint16	data_
	Internal binary representation. More...

Static Private Attributes
static const std::float_round_style	round_style = (std::float_round_style)( 1 )
	Rounding mode to use. More...

Friends
struct	detail::functions
struct	detail::unary_specialized< half >
struct	detail::binary_specialized< half, half >
template<typename , typename , std::float_round_style >
struct	detail::half_caster
class	std::numeric_limits< half >
template<typename , typename , std::float_round_style >
struct	detail::half_caster

Detailed Description

Half-precision floating point type.

This class implements an IEEE-conformant half-precision floating point type with the usual arithmetic operators and conversions. It is implicitly convertible to single-precision floating point, which makes artihmetic expressions and functions with mixed-type operands to be of the most precise operand type. Additionally all arithmetic operations (and many mathematical functions) are carried out in single-precision internally. All conversions from single- to half-precision are done using the library's default rounding mode, but temporary results inside chained arithmetic expressions are kept in single-precision as long as possible (while of course still maintaining a strong half-precision type).

According to the C++98/03 definition, the half type is not a POD type. But according to C++11's less strict and extended definitions it is both a standard layout type and a trivially copyable type (even if not a POD type), which means it can be standard-conformantly copied using raw binary copies. But in this context some more words about the actual size of the type. Although the half is representing an IEEE 16-bit type, it does not neccessarily have to be of exactly 16-bits size. But on any reasonable implementation the actual binary representation of this type will most probably not ivolve any additional "magic" or padding beyond the simple binary representation of the underlying 16-bit IEEE number, even if not strictly guaranteed by the standard. But even then it only has an actual size of 16 bits if your C++ implementation supports an unsigned integer type of exactly 16 bits width. But this should be the case on nearly any reasonable platform.

So if your C++ implementation is not totally exotic or imposes special alignment requirements, it is a reasonable assumption that the data of a half is just comprised of the 2 bytes of the underlying IEEE representation.

Constructor & Destructor Documentation

half() [1/8]

half_float::half::half ( )

inline

Default constructor.

This initializes the half to 0. Although this does not match the builtin types' default-initialization semantics and may be less efficient than no initialization, it is needed to provide proper value-initialization semantics.

half() [2/8]

half_float::half::half ( detail::expr  rhs )

inline

Copy constructor.

Template Parameters

T	type of concrete half expression

Parameters

rhs	half expression to copy from

half() [3/8]

half_float::half::half ( float  rhs )

inlineexplicit

Conversion constructor.

Parameters

rhs	float to convert

half() [4/8]

half_float::half::half ( detail::binary_t  , detail::uint16  bits  )

inlineprivate

Constructor.

Parameters

bits	binary representation to set half to

half() [5/8]

half_float::half::half ( )

inline

Default constructor.

This initializes the half to 0. Although this does not match the builtin types' default-initialization semantics and may be less efficient than no initialization, it is needed to provide proper value-initialization semantics.

half() [6/8]

half_float::half::half ( detail::expr  rhs )

inline

Copy constructor.

Template Parameters

T	type of concrete half expression

Parameters

rhs	half expression to copy from

half() [7/8]

half_float::half::half ( float  rhs )

inlineexplicit

Conversion constructor.

Parameters

rhs	float to convert

half() [8/8]

half_float::half::half ( detail::binary_t  , detail::uint16  bits  )

inlineprivate

Constructor.

Parameters

bits	binary representation to set half to

Member Function Documentation

operator float() [1/2]

half_float::half::operator float ( ) const

inline

Conversion to single-precision.

Returns

single precision value representing expression value

operator=() [1/4]

half& half_float::half::operator= ( detail::expr  rhs )

inline

Assignment operator.

Template Parameters

T	type of concrete half expression

Parameters

rhs	half expression to copy from

Returns

reference to this half

operator+=() [1/4]

template<typename T >

detail::enable<half&,T>::type half_float::half::operator+= ( T  rhs )

inline

Arithmetic assignment.

Template Parameters

T	type of concrete half expression

Parameters

rhs	half expression to add

Returns

reference to this half

operator-=() [1/4]

template<typename T >

detail::enable<half&,T>::type half_float::half::operator-= ( T  rhs )

inline

Arithmetic assignment.

Template Parameters

T	type of concrete half expression

Parameters

rhs	half expression to subtract

Returns

reference to this half

operator*=() [1/4]

template<typename T >

detail::enable<half&,T>::type half_float::half::operator*= ( T  rhs )

inline

Arithmetic assignment.

Template Parameters

T	type of concrete half expression

Parameters

rhs	half expression to multiply with

Returns

reference to this half

operator/=() [1/4]

template<typename T >

detail::enable<half&,T>::type half_float::half::operator/= ( T  rhs )

inline

Arithmetic assignment.

Template Parameters

T	type of concrete half expression

Parameters

rhs	half expression to divide by

Returns

reference to this half

operator=() [2/4]

half& half_float::half::operator= ( float  rhs )

inline

Assignment operator.

Parameters

rhs	single-precision value to copy from

Returns

reference to this half

operator+=() [2/4]

half& half_float::half::operator+= ( float  rhs )

inline

Arithmetic assignment.

Parameters

rhs	single-precision value to add

Returns

reference to this half

operator-=() [2/4]

half& half_float::half::operator-= ( float  rhs )

inline

Arithmetic assignment.

Parameters

rhs	single-precision value to subtract

Returns

reference to this half

operator*=() [2/4]

half& half_float::half::operator*= ( float  rhs )

inline

Arithmetic assignment.

Parameters

rhs	single-precision value to multiply with

Returns

reference to this half

operator/=() [2/4]

half& half_float::half::operator/= ( float  rhs )

inline

Arithmetic assignment.

Parameters

rhs	single-precision value to divide by

Returns

reference to this half

operator++() [1/4]

half& half_float::half::operator++ ( )

inline

Prefix increment.

Returns

incremented half value

operator--() [1/4]

half& half_float::half::operator-- ( )

inline

Prefix decrement.

Returns

decremented half value

operator++() [2/4]

half half_float::half::operator++ ( int  )

inline

Postfix increment.

Returns

non-incremented half value

operator--() [2/4]

half half_float::half::operator-- ( int  )

inline

Postfix decrement.

Returns

non-decremented half value

operator float() [2/2]

half_float::half::operator float ( ) const

inline

Conversion to single-precision.

Returns

single precision value representing expression value

operator=() [3/4]

half& half_float::half::operator= ( detail::expr  rhs )

inline

Assignment operator.

Template Parameters

T	type of concrete half expression

Parameters

rhs	half expression to copy from

Returns

reference to this half

operator+=() [3/4]

template<typename T >

detail::enable<half&, T>::type half_float::half::operator+= ( T  rhs )

inline

Arithmetic assignment.

Template Parameters

T	type of concrete half expression

Parameters

rhs	half expression to add

Returns

reference to this half

operator-=() [3/4]

template<typename T >

detail::enable<half&, T>::type half_float::half::operator-= ( T  rhs )

inline

Arithmetic assignment.

Template Parameters

T	type of concrete half expression

Parameters

rhs	half expression to subtract

Returns

reference to this half

operator*=() [3/4]

template<typename T >

detail::enable<half&, T>::type half_float::half::operator*= ( T  rhs )

inline

Arithmetic assignment.

Template Parameters

T	type of concrete half expression

Parameters

rhs	half expression to multiply with

Returns

reference to this half

operator/=() [3/4]

template<typename T >

detail::enable<half&, T>::type half_float::half::operator/= ( T  rhs )

inline

Arithmetic assignment.

Template Parameters

T	type of concrete half expression

Parameters

rhs	half expression to divide by

Returns

reference to this half

operator=() [4/4]

half& half_float::half::operator= ( float  rhs )

inline

Assignment operator.

Parameters

rhs	single-precision value to copy from

Returns

reference to this half

operator+=() [4/4]

half& half_float::half::operator+= ( float  rhs )

inline

Arithmetic assignment.

Parameters

rhs	single-precision value to add

Returns

reference to this half

operator-=() [4/4]

half& half_float::half::operator-= ( float  rhs )

inline

Arithmetic assignment.

Parameters

rhs	single-precision value to subtract

Returns

reference to this half

operator*=() [4/4]

half& half_float::half::operator*= ( float  rhs )

inline

Arithmetic assignment.

Parameters

rhs	single-precision value to multiply with

Returns

reference to this half

operator/=() [4/4]

half& half_float::half::operator/= ( float  rhs )

inline

Arithmetic assignment.

Parameters

rhs	single-precision value to divide by

Returns

reference to this half

operator++() [3/4]

half& half_float::half::operator++ ( )

inline

Prefix increment.

Returns

incremented half value

operator--() [3/4]

half& half_float::half::operator-- ( )

inline

Prefix decrement.

Returns

decremented half value

operator++() [4/4]

half half_float::half::operator++ ( int  )

inline

Postfix increment.

Returns

non-incremented half value

operator--() [4/4]

half half_float::half::operator-- ( int  )

inline

Postfix decrement.

Returns

non-decremented half value

Friends And Related Function Documentation

detail::functions

detail::functions

friend

detail::unary_specialized< half >

friend struct detail::unary_specialized< half >

friend

detail::binary_specialized< half, half >

friend struct detail::binary_specialized< half, half >

friend

detail::half_caster [1/2]

template<typename , typename , std::float_round_style >

friend struct detail::half_caster

friend

std::numeric_limits< half >

friend class std::numeric_limits< half >

friend

detail::half_caster [2/2]

template<typename , typename , std::float_round_style >

struct detail::half_caster

friend

Member Data Documentation

round_style

static const std::float_round_style half_float::half::round_style = (std::float_round_style)( 1 )

staticprivate

Rounding mode to use.

data_

detail::uint16 half_float::half::data_

private

Internal binary representation.

---

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

• ieee_half.h
• samples/common/half.h