Exiv2 - Image metadata library and tools

Template for a Value of a basic type. This is used for unsigned and signed short, long and rationals. More...

#include <value.hpp>

Inheritance diagram for Exiv2::ValueType< T >:

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

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

Public Member Functions
int64_t toInt64 (size_t n) const
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) const
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.

int64_t toInt64 (size_t n) const
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) const
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.

int64_t toInt64 (size_t n) const
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) const
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.

int64_t toInt64 (size_t n) const
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) const
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) const
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) const
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) const
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.

Rational toRational (size_t n) const
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.

Rational toRational (size_t n) const
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.

Rational toRational (size_t n) const
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.

Creators
ValueType ()
Default Constructor.

ValueType (const byte *buf, size_t len, ByteOrder byteOrder, TypeId typeId=getType< T >())
Constructor.

ValueType (const T &val, TypeId typeId=getType< T >())
Constructor.

ValueType (const ValueType< T > &rhs)
Copy constructor.

~ValueType () override
Virtual destructor.

Manipulators
ValueType< T > & operator= (const ValueType< T > &rhs)
Assignment operator.

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

int read (const std::string &buf) override
Set the data from a string of values of type T (e.g., "0 1 2 3" or "1/2 1/3 1/4" depending on what T is). Generally, the accepted input format is the same as that produced by the write() method.

int setDataArea (const byte *buf, size_t len) override
Set the data area. This method copies (clones) the buffer pointed to by buf.

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.

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.

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

Accessors
using ValueList = std::vector< T >
Container for values.

using iterator = typename std::vector< T >::iterator
Iterator type defined for convenience.

using const_iterator = typename std::vector< T >::const_iterator
Const iterator type defined for convenience.

ValueList value_
The container for all values. In your application, if you know what subclass of Value you're dealing with (and possibly the T) then you can access this STL container through the usual standard library functions.

UniquePtr clone () const

size_t copy (byte *buf, ByteOrder byteOrder) const override
Write value to a 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.

size_t sizeDataArea () const override
Return the size of the data area.

DataBuf dataArea () const override
Return a copy of the data area in a DataBuf. The caller owns this copy and DataBuf ensures that it will be deleted.

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

template<typename T>
class Exiv2::ValueType< T >

Template for a Value of a basic type. This is used for unsigned and signed short, long and rationals.

Examples: addmoddel.cpp.

Member Function Documentation

◆ copy()

template<typename T >

size_t Exiv2::ValueType< T >::copy	(	byte *	buf,
		ByteOrder	byteOrder
	)		const

overridevirtual

Write value to a data buffer.

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	Applicable byte order (little or big endian).

Returns: Number of bytes written.

Implements Exiv2::Value.

References Exiv2::toData().

◆ count()

template<typename T >

size_t Exiv2::ValueType< T >::count ( ) const

overridevirtual

Return the number of components of the value.

Implements Exiv2::Value.

◆ dataArea()

template<typename T >

DataBuf Exiv2::ValueType< T >::dataArea ( ) const

overridevirtual

Return a copy of the data area in a DataBuf. The caller owns this copy and DataBuf ensures that it will be deleted.

Reimplemented from Exiv2::Value.

◆ read() [1/2]

template<typename T >

int Exiv2::ValueType< T >::read	(	const byte *	buf,
		size_t	len,
		ByteOrder	byteOrder
	)

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.

Examples: addmoddel.cpp.

References Exiv2::TypeInfo::typeSize().

Referenced by Exiv2::ValueType< T >::ValueType().

◆ read() [2/2]

template<typename T >

int Exiv2::ValueType< T >::read ( const std::string & buf )

overridevirtual

Set the data from a string of values of type T (e.g., "0 1 2 3" or "1/2 1/3 1/4" depending on what T is). Generally, the accepted input format is the same as that produced by the write() method.

Implements Exiv2::Value.

◆ setDataArea()

template<typename T >

int Exiv2::ValueType< T >::setDataArea	(	const byte *	buf,
		size_t	len
	)

overridevirtual

Set the data area. This method copies (clones) the buffer pointed to by buf.

Reimplemented from Exiv2::Value.

◆ size()

template<typename T >

size_t Exiv2::ValueType< T >::size ( ) const

overridevirtual

Return the size of the value in bytes.

Implements Exiv2::Value.

References Exiv2::TypeInfo::typeSize().

◆ sizeDataArea()

template<typename T >

size_t Exiv2::ValueType< T >::sizeDataArea ( ) const

overridevirtual

Return the size of the data area.

Reimplemented from Exiv2::Value.

◆ toFloat() [1/3]

float Exiv2::ValueType< Rational >::toFloat ( size_t n ) const

inlinevirtual

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.

◆ toFloat() [2/3]

float Exiv2::ValueType< URational >::toFloat ( size_t n ) const

inlinevirtual

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.

◆ toFloat() [3/3]

template<typename T >

float Exiv2::ValueType< T >::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() [1/5]

int64_t Exiv2::ValueType< double >::toInt64 ( size_t n ) const

inlinevirtual

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.

◆ toInt64() [2/5]

int64_t Exiv2::ValueType< float >::toInt64 ( size_t n ) const

inlinevirtual

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.

◆ toInt64() [3/5]

int64_t Exiv2::ValueType< Rational >::toInt64 ( size_t n ) const

inlinevirtual

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.

◆ toInt64() [4/5]

int64_t Exiv2::ValueType< URational >::toInt64 ( size_t n ) const

inlinevirtual

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.

◆ toInt64() [5/5]

template<typename T >

int64_t Exiv2::ValueType< T >::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() [1/5]

Rational Exiv2::ValueType< Rational >::toRational ( size_t n ) const

inlinevirtual

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.

◆ toRational() [2/5]

Rational Exiv2::ValueType< URational >::toRational ( size_t n ) const

inlinevirtual

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.

◆ toRational() [3/5]

Rational Exiv2::ValueType< float >::toRational ( size_t n ) const

inlinevirtual

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.

References Exiv2::floatToRationalCast().

◆ toRational() [4/5]

Rational Exiv2::ValueType< double >::toRational ( size_t n ) const

inlinevirtual

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.

References Exiv2::floatToRationalCast().

◆ toRational() [5/5]

template<typename T >

Rational Exiv2::ValueType< T >::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()

template<typename T >

std::string Exiv2::ValueType< T >::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() [1/5]

uint32_t Exiv2::ValueType< double >::toUint32 ( size_t n ) const

inlinevirtual

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.

◆ toUint32() [2/5]

uint32_t Exiv2::ValueType< float >::toUint32 ( size_t n ) const

inlinevirtual

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.

◆ toUint32() [3/5]

uint32_t Exiv2::ValueType< Rational >::toUint32 ( size_t n ) const

inlinevirtual

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.

◆ toUint32() [4/5]

uint32_t Exiv2::ValueType< URational >::toUint32 ( size_t n ) const

inlinevirtual

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.

◆ toUint32() [5/5]

template<typename T >

uint32_t Exiv2::ValueType< T >::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()

template<typename T >

std::ostream & Exiv2::ValueType< T >::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()

◆ dataArea()

◆ read() [1/2]

◆ read() [2/2]

◆ setDataArea()

◆ size()

◆ sizeDataArea()

◆ toFloat() [1/3]

◆ toFloat() [2/3]

◆ toFloat() [3/3]

◆ toInt64() [1/5]

◆ toInt64() [2/5]

◆ toInt64() [3/5]

◆ toInt64() [4/5]

◆ toInt64() [5/5]

◆ toRational() [1/5]

◆ toRational() [2/5]

◆ toRational() [3/5]

◆ toRational() [4/5]

◆ toRational() [5/5]

◆ toString()

◆ toUint32() [1/5]

◆ toUint32() [2/5]

◆ toUint32() [3/5]

◆ toUint32() [4/5]

◆ toUint32() [5/5]

◆ write()