Value for an undefined data type. More...

#include <value.hpp>

Inheritance diagram for Exiv2::DataValue:

Public Types
using	UniquePtr = std::unique_ptr< DataValue >
	Shortcut for a DataValue auto pointer.

Public Types inherited from Exiv2::Value
using	UniquePtr = std::unique_ptr< Value >
	Shortcut for a Value auto pointer.

Public Member Functions
	DataValue (TypeId typeId=undefined)

	DataValue (const byte *buf, size_t len, ByteOrder byteOrder=invalidByteOrder, TypeId typeId=undefined)

Manipulators
int	read (const byte *buf, size_t len, ByteOrder byteOrder=invalidByteOrder) override
	Read the value from a character buffer.

int	read (const std::string &buf) override
	Set the data from a string of integer values (e.g., "0 1 2 3")

Public Member Functions inherited from Exiv2::Value
	Value (TypeId typeId)
	Constructor, taking a type id to initialize the base class with.

virtual	~Value ()=default
	Virtual destructor.

virtual int	setDataArea (const byte *buf, size_t len)
	Set the data area, if the value has one by copying (cloning) the buffer pointed to by buf.

TypeId	typeId () const
	Return the type identifier (Exif data format type).

UniquePtr	clone () const
	Return an auto-pointer to a copy of itself (deep copy). The caller owns this copy and the auto-pointer ensures that it will be deleted.

std::string	toString () const
	Return the value as a string. Implemented in terms of write(std::ostream& os) const of the concrete class.

virtual size_t	sizeDataArea () const
	Return the size of the data area, 0 if there is none.

virtual DataBuf	dataArea () const
	Return a copy of the data area if the value has one. The caller owns this copy and DataBuf ensures that it will be deleted.

bool	ok () const
	Check the ok status indicator. After a to<Type> conversion, this indicator shows whether the conversion was successful.

Accessors
UniquePtr	clone () const

size_t	copy (byte *buf, ByteOrder byteOrder=invalidByteOrder) const override
	Write value to a character data buffer.

size_t	count () const override
	Return the number of components of the value.

size_t	size () const override
	Return the size of the value in bytes.

std::ostream &	write (std::ostream &os) const override
	Write the value to an output stream. You do not usually have to use this function; it is used for the implementation of the output operator for Value, operator<<(std::ostream &os, const Value &value).

std::string	toString (size_t n) const override
	Return the n-th component of the value as a string. The behaviour of this method may be undefined if there is no n-th component.

int64_t	toInt64 (size_t n=0) const override
	Convert the n-th component of the value to an int64_t. The behaviour of this method may be undefined if there is no n-th component.

uint32_t	toUint32 (size_t n=0) const override
	Convert the n-th component of the value to a float. The behaviour of this method may be undefined if there is no n-th component.

float	toFloat (size_t n=0) const override
	Convert the n-th component of the value to a float. The behaviour of this method may be undefined if there is no n-th component.

Rational	toRational (size_t n=0) const override
	Convert the n-th component of the value to a Rational. The behaviour of this method may be undefined if there is no n-th component.

Additional Inherited Members
Static Public Member Functions inherited from Exiv2::Value
static UniquePtr	create (TypeId typeId)
	A (simple) factory to create a Value type.

Protected Member Functions inherited from Exiv2::Value
	Value (const Value &)=default

Value &	operator= (const Value &)=default
	Assignment operator. Protected so that it can only be used by subclasses but not directly.

Protected Attributes inherited from Exiv2::Value
bool	ok_ {true}
	Indicates the status of the previous to<Type> conversion.

Detailed Description

Value for an undefined data type.

Member Function Documentation

◆ copy()

size_t Exiv2::DataValue::copy	(	byte *	buf,
		ByteOrder	byteOrder = `invalidByteOrder`
	)		const

overridevirtual

Write value to a character data buffer.

Note: The byte order is required by the interface but not used by this method, so just use the default.

The user must ensure that the buffer has enough memory. Otherwise the call results in undefined behaviour.

Parameters

buf	Data buffer to write to.
byteOrder	Byte order. Not needed.

Returns: Number of characters written.

Implements Exiv2::Value.

◆ count()

size_t Exiv2::DataValue::count ( ) const

overridevirtual

Return the number of components of the value.

Implements Exiv2::Value.

◆ read() [1/2]

int Exiv2::DataValue::read	(	const byte *	buf,
		size_t	len,
		ByteOrder	byteOrder = `invalidByteOrder`
	)

overridevirtual

Read the value from a character buffer.

Parameters

buf	Pointer to the data buffer to read from
len	Number of bytes in the data buffer
byteOrder	Applicable byte order (little or big endian).

Returns: 0 if successful.

Implements Exiv2::Value.

◆ read() [2/2]

int Exiv2::DataValue::read ( const std::string & buf )

overridevirtual

Set the data from a string of integer values (e.g., "0 1 2 3")

Implements Exiv2::Value.

◆ size()

size_t Exiv2::DataValue::size ( ) const

overridevirtual

Return the size of the value in bytes.

Implements Exiv2::Value.

◆ toFloat()

float Exiv2::DataValue::toFloat ( size_t n = 0 ) const

overridevirtual

Convert the n-th component of the value to a float. The behaviour of this method may be undefined if there is no n-th component.

Returns: The converted value.

Implements Exiv2::Value.

◆ toInt64()

int64_t Exiv2::DataValue::toInt64 ( size_t n = 0 ) const

overridevirtual

Convert the n-th component of the value to an int64_t. The behaviour of this method may be undefined if there is no n-th component.

Returns: The converted value.

Implements Exiv2::Value.

◆ toRational()

Rational Exiv2::DataValue::toRational ( size_t n = 0 ) const

overridevirtual

Convert the n-th component of the value to a Rational. The behaviour of this method may be undefined if there is no n-th component.

Returns: The converted value.

Implements Exiv2::Value.

◆ toString()

std::string Exiv2::DataValue::toString ( size_t n ) const

overridevirtual

Return the n-th component of the value as a string. The behaviour of this method may be undefined if there is no n-th component.

Reimplemented from Exiv2::Value.

◆ toUint32()

uint32_t Exiv2::DataValue::toUint32 ( size_t n = 0 ) const

overridevirtual

Convert the n-th component of the value to a float. The behaviour of this method may be undefined if there is no n-th component.

Returns: The converted value.

Implements Exiv2::Value.

◆ write()

std::ostream & Exiv2::DataValue::write ( std::ostream & os ) const

overridevirtual

Write the value to an output stream. You do not usually have to use this function; it is used for the implementation of the output operator for Value, operator<<(std::ostream &os, const Value &value).

Implements Exiv2::Value.

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

value.hpp

Public Types

Public Member Functions

Accessors

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ copy()

◆ count()

◆ read() [1/2]

◆ read() [2/2]

◆ size()

◆ toFloat()

◆ toInt64()

◆ toRational()

◆ toString()

◆ toUint32()

◆ write()