A type-wrapper that provides transparent access to a range of memory in a message buffer as if it were the specified type itself. More...

#include <datum.h>

Inheritance diagram for Hg::Datum< Idx, format_t >:

Public Types
typedef detail::DefineFieldType< Idx, format_t >::type	field_type
	Type mapping for the message format type to the actual value_type.

typedef format_t	format_type
	format of the parent TypeList.

typedef field_type::index_type	index_type
	The type extracted at the current index defined in the parent TypeList.

typedef field_type::value_type	value_type
	The data type managed by this Datum. This is the type of data that will be written to the attached buffer.

Public Types inherited from Hg::detail::FieldTypes< FieldT, TraitT >
typedef FieldT	index_type
	The type at the index of the parent type container.

typedef field_data_t < index_type >::value_type	value_type
	The specified value type for the current Datum.

Public Member Functions
	Datum ()
	Default Constructor.

	Datum (Datum &datum)
	Copy Constructor. More...

void	clear ()
	Zeros the datum.

bool	equivalent (const value_type &rhs) const
	Indicates equivalency for a value_type and this Datum's value. More...

const value_type &	get () const
	Returns the current value of this Datum. More...

value_type &	get ()
	Returns a reference to the value managed in this datum.

bool	less (const value_type &rhs) const
	Compares a value_type against this Datum's value for less-than relationship. More...

	operator value_type () const
	Operator to value_type. More...

bool	operator!= (const value_type &rhs) const
	Inequality Value Comparison (value_type) More...

bool	operator< (const value_type &rhs) const
	less Than Value Comparison (value_type) More...

bool	operator<= (const value_type &rhs) const
	less Than or equal Value Comparison (value_type) More...

Datum &	operator= (const Datum &rhs)
	Assignment Operator. More...

Datum &	operator= (value_type rhs)
	Assignment Operator (value_type) More...

bool	operator== (const value_type &rhs) const
	Equality Value Comparison (value_type) More...

bool	operator> (const value_type &rhs) const
	Greater Than Value Comparison (value_type) More...

bool	operator>= (const value_type &rhs) const
	Greater Than or equal Value Comparison (value_type) More...

void	set (const value_type &value)
	Updates the value of this Datum. More...

Public Member Functions inherited from Hg::detail::FieldTypes< FieldT, TraitT >
const value_type &	data () const
	Returns the value of the data buffer.

void	data (const value_type &value)
	Returns the value of the data buffer.

value_type &	reference ()
	Returns a reference to the internal data storage. More...

Static Public Attributes
static const size_t	k_offset = OffsetOf<Idx, format_t>::value
	The offset in the buffer where this msg field is located.

Protected Member Functions
const value_type &	get_data () const
	Returns the value of the data buffer.

value_type &	get_reference ()
	Returns a reference to the internal data storage. More...

void	set_data (const value_type &value)
	Returns the value of the data buffer.

Additional Inherited Members
Protected Attributes inherited from Hg::detail::FieldTypes< FieldT, TraitT >
value_type	m_data
	This is a local copy of the data value to shadow the value held in the buffer.

Detailed Description

template<size_t Idx, typename format_t>
class Hg::Datum< Idx, format_t >

A type-wrapper that provides transparent access to a range of memory in a message buffer as if it were the specified type itself.

The Datum<> is intended to be used as if it were the direct field itself. All details of byte-order and memory-alignment are handled internally by the buffers the Datum<> instance is mapped to.

Parameters

Idx	[size_t] The index of this element in the TypeList definition. Idx must be < length<T>::value.
format_t	[typename] The TypeList that contains this elements definition. T must be an indexable type container.

Note: Parameterized type T is verified by the compiler to be A type container.

Definition at line 41 of file datum.h.

Constructor & Destructor Documentation

template<size_t Idx, typename format_t>

Hg::Datum< Idx, format_t >::Datum ( Datum< Idx, format_t > & datum )

inline

Copy Constructor.

Makes a complete copy of an existing Datum object.

Parameters

datum A reference to the Another instance of a Datum.

Definition at line 88 of file datum.h.

Member Function Documentation

template<size_t Idx, typename format_t>

bool Hg::Datum< Idx, format_t >::equivalent ( const value_type & rhs ) const

inline

Indicates equivalency for a value_type and this Datum's value.

Parameters

rhs	A value_type value to compare with the value of this instance.

Definition at line 289 of file datum.h.

template<size_t Idx, typename format_t>

const value_type& Hg::Datum< Idx, format_t >::get ( ) const

inline

Returns the current value of this Datum.

If a buffer is attached to this message field, the value will be read from the buffer. Otherwise the data will be returned. This const version will not update the data from the buffer.

Returns: The value of this Datum is returned. If a valid buffer is associated with this field, the data referenced in the buffer is returned. Otherwise the temporary locally cached value is returned.

Definition at line 256 of file datum.h.

template<size_t Idx, typename format_t>

value_type& Hg::Datum< Idx, format_t >::get_reference ( )

inlineprotected

Returns a reference to the internal data storage.

Returns a reference to the internal data storage managed by this Datum. The reference to the data can be useful, and necessary for

Definition at line 312 of file datum.h.

template<size_t Idx, typename format_t>

bool Hg::Datum< Idx, format_t >::less ( const value_type & rhs ) const

inline

Compares a value_type against this Datum's value for less-than relationship.

Parameters

rhs	A value_type value to compare with the value of this instance.

Definition at line 300 of file datum.h.

template<size_t Idx, typename format_t>

Hg::Datum< Idx, format_t >::operator value_type ( ) const

inline

Operator to value_type.

Allows this Datum object to be converted to the value_type managed by this object. The value returned comes from the data buffer.

Returns: The current value of this object is returned.

Definition at line 162 of file datum.h.

template<size_t Idx, typename format_t>

bool Hg::Datum< Idx, format_t >::operator!= ( const value_type & rhs ) const

inline

Inequality Value Comparison (value_type)

Parameters

rhs	A value_type value to compare with the value of this instance.

Definition at line 185 of file datum.h.

template<size_t Idx, typename format_t>

bool Hg::Datum< Idx, format_t >::operator< ( const value_type & rhs ) const

inline

less Than Value Comparison (value_type)

Parameters

rhs	A value_type value to compare with the value of this instance.

Definition at line 196 of file datum.h.

template<size_t Idx, typename format_t>

bool Hg::Datum< Idx, format_t >::operator<= ( const value_type & rhs ) const

inline

less Than or equal Value Comparison (value_type)

Parameters

rhs	A value_type value to compare with the value of this instance.

Definition at line 207 of file datum.h.

template<size_t Idx, typename format_t>

Datum& Hg::Datum< Idx, format_t >::operator= ( const Datum< Idx, format_t > & rhs )

inline

Assignment Operator.

Allows assignment of the Datum value. Associated buffers are not changed through assignment.

Parameters

rhs	A different instance of a Datum object whose value will be copied into this instance.

Definition at line 131 of file datum.h.

template<size_t Idx, typename format_t>

Datum& Hg::Datum< Idx, format_t >::operator= ( value_type rhs )

inline

Assignment Operator (value_type)

Allows assignment to this Datum type from it's parameter type, value_type. This function is the key to allowing the Datum to behave as if the assignment was performed directly on the the managed type.

Parameters

rhs	A value of the Datum value_type that will be used to directly modify the value of the object.

Definition at line 148 of file datum.h.

template<size_t Idx, typename format_t>

bool Hg::Datum< Idx, format_t >::operator== ( const value_type & rhs ) const

inline

Equality Value Comparison (value_type)

Parameters

rhs	A value_type value to compare with the value of this instance.

Definition at line 174 of file datum.h.

template<size_t Idx, typename format_t>

bool Hg::Datum< Idx, format_t >::operator> ( const value_type & rhs ) const

inline

Greater Than Value Comparison (value_type)

Parameters

rhs	A value_type value to compare with the value of this instance.

Definition at line 230 of file datum.h.

template<size_t Idx, typename format_t>

bool Hg::Datum< Idx, format_t >::operator>= ( const value_type & rhs ) const

inline

Greater Than or equal Value Comparison (value_type)

Parameters

rhs	A value_type value to compare with the value of this instance.

Definition at line 219 of file datum.h.

template<size_t Idx, typename format_t>

void Hg::Datum< Idx, format_t >::set ( const value_type & value )

inline

Updates the value of this Datum.

Parameters

value The value to assign to this object. The local cached value will be updated. If a buffer has been associated with this object, its data will be updated with the value as well.

Definition at line 278 of file datum.h.

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

datum.h

Public Types

Public Member Functions

Static Public Attributes

Protected Member Functions

Additional Inherited Members

Detailed Description

template<size_t Idx, typename format_t> class Hg::Datum< Idx, format_t >

Constructor & Destructor Documentation

Member Function Documentation

template<size_t Idx, typename format_t>
class Hg::Datum< Idx, format_t >