FCam::TagValue Class Reference

The values with which a Device can tag a Frame. More...

Collaboration diagram for FCam::TagValue:

List of all members.

Public Types
enum	Type {   Null = 0, Int, Float, Double,   String, Time, IntVector, FloatVector,   DoubleVector, StringVector, TimeVector }
	A TagValue can represent one of a number of types listed below. More...
Public Member Functions
bool	valid ()
	Does this tag exist? That is, is type equal to Null.
std::string	toString () const
	Serialize into a human-and-python readable format.
std::string	toBlob () const
	Serialize into a more efficient binary format.
Constructors
TagValues can be constructed from many different types. The default constructor makes a Null TagValue. Each other constructor makes a copy of its argument.
	TagValue ()
	TagValue (int)
	TagValue (float)
	TagValue (double)
	TagValue (std::string)
	TagValue (FCam::Time)
	TagValue (std::vector< int >)
	TagValue (std::vector< float >)
	TagValue (std::vector< double >)
	TagValue (std::vector< std::string >)
	TagValue (std::vector< FCam::Time >)
	TagValue (const TagValue &)
Assignment
You assign to a TagValue from any of the types a TagValue supports. This sets the TagValue to a copy of the argument.
const TagValue &	operator= (const int &)
const TagValue &	operator= (const float &)
const TagValue &	operator= (const double &)
const TagValue &	operator= (const std::string &)
const TagValue &	operator= (const FCam::Time &)
const TagValue &	operator= (const std::vector< int > &)
const TagValue &	operator= (const std::vector< float > &)
const TagValue &	operator= (const std::vector< double > &)
const TagValue &	operator= (const std::vector< std::string > &)
const TagValue &	operator= (const std::vector< FCam::Time > &)
const TagValue &	operator= (const TagValue &)
Cast Operators
A TagValue can be implicitly cast to the appropriate type. Trying to cast a TagValue to the wrong type will result in a default value returned and a BadCast error placed on the event queue. If you wish to inspect or modify a large tag value in-place (e.g. an IntVector), cast it to a reference to the appropriate type, rather than a concrete instance of that type. The latter will make a fresh copy of the potentially large data. For example: Frame frame = Sensor.getFrame(); // This makes a copy of a potentially large array std::vector<int> bigTag = frame["bigTag"]; // This does not, and so is usually what you want to do. std::vector<int> &bigTagRef = frame["bigTag"];
	operator int & () const
	operator float & () const
	operator double & () const
	operator std::string & () const
	operator FCam::Time & () const
	operator std::vector< int > & () const
	operator std::vector< float > & () const
	operator std::vector< double > & () const
	operator std::vector< std::string > & () const
	operator std::vector< FCam::Time > & () const
Cast methods
A TagValue also has explicit methods to cast it to various types. These have the same semantics as the implicit casts, but are more readable in many cases. For example: TagValue tag = std::vector<int>(); // Use the overloaded cast operator ((std::vector<int> &)tag).push_back(3); // Do the same thing using the cast method tag.asIntVector().push_back(3);
int &	asInt ()
float &	asFloat ()
double &	asDouble ()
std::string &	asString ()
FCam::Time &	asTime ()
std::vector< int > &	asIntVector ()
std::vector< float > &	asFloatVector ()
std::vector< double > &	asDoubleVector ()
std::vector< std::string > &	asStringVector ()
std::vector< FCam::Time > &	asTimeVector ()
Static Public Member Functions
static TagValue	fromString (const std::string &)
	Deserialize from either format.
Public Attributes
Type	type
	The type of this tag.
void *	data
	A pointer to the actual value of this tag.
Related Functions
(Note that these are not member functions.)
std::ostream &	operator<< (std::ostream &out, const TagValue &t)
	Serialize the TagValue into a human readable format.
std::istream &	operator>> (std::istream &in, TagValue &t)
	Deserialize a TagValue from either the human-readable or the binary format.

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Detailed Description

The values with which a Device can tag a Frame.

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Member Enumeration Documentation

enum FCam::TagValue::Type

A TagValue can represent one of a number of types listed below.

Enumerator:

Null	A Null TagValue represents nothing, and indicates no such tag exists.
Int	A 32-bit signed integer.
Float	A 32-bit float.
Double	A 64-bit double.
String	An std::string. Also useful to represent a blob of binary data.
Time	A Time.
IntVector	A std::vector of ints.
FloatVector	A std::vector of floats.
DoubleVector	A std::vector of doubles.
StringVector	A std::vector of std::strings.
TimeVector	A std::vector of Times.

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Member Function Documentation

bool FCam::TagValue::valid

(

)

[inline]

Does this tag exist? That is, is type equal to Null.

std::string FCam::TagValue::toBlob

(

)

const

Serialize into a more efficient binary format.

For tags containing large arrays of data, this format can be over 100x more time-efficient than the human readable format, and about 2.5x more space efficient.

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Friends And Related Function Documentation

std::istream & operator>>	(	std::istream &	in,
		TagValue &	t
	)			[related]

Deserialize a TagValue from either the human-readable or the binary format.

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Member Data Documentation

Type FCam::TagValue::type

The type of this tag.

void* FCam::TagValue::data

A pointer to the actual value of this tag.