MCVariantType Class Reference

Base class for all variant data types. More...

#include <mcllib/MCVariant.h>

Inheritance diagram for MCVariantType:

List of all members.

Public Types
typedef const MCVariantType &	constref_MCVariantType
	Type of a const regeference to a variant type.
Public Member Functions
mcuint32	getTypeId () const
	Obtain the internal type identifier for the variant.
const MCString &	getTypeName () const
	Get the name of the type of this variant.
bool	isDefined () const
	Determine if the variant value is undefined.
	MCVariantType (const MCVariantType &vt)
	Copy constructor.
	MCVariantType ()
	Default constructor.
	operator bool () const
	Determine if the variant value can be considered true.
bool	operator< (const MCVariantType &vt) const
	Test if this variant type is less than another.
MCVariantType &	operator= (const MCVariantType &vt)
	Assigment.
bool	operator== (const MCVariantType &vt) const
	Test if this variant type is equal to another.
void	put (MCStringStream &os) const
	Put to a string stream.
void	put (MCSerializer &serializer) const
	Put to a serializer (serialize it).
MCString	toString () const
	Get a string representation of the value.
	~MCVariantType ()
	Destructor.
Static Public Member Functions
mcuint32	getTypeId (const char *typeName)
	Obtain the type id for a type name.
const MCString &	getTypeName (mcuint32 typeId)
	Get the type name of a type id.
MCVariantType	parse (const MCString &val)
	Parse a string and return a variant object for that string If the string is an empty string, or the special string "null" (excluding quotes and irrespective of case), an undefined variant value is returned.
Protected Member Functions
mclpriv::MCVTImpl *	getImpl ()
	Obtain the private implementation contained in the variant type.
const mclpriv::MCVTImpl *	getImpl () const
	Obtain the private implementation contained in the variant type.
	MCVariantType (const MCVariantType &vt, mcuint32 type)
	Constructor used by derived types.
	MCVariantType (mcuint32 type)
	Constructor used by derived types.
Friends
MCStringStream &	operator<< (MCStringStream &os, MCVariantType &vt)
	Alternative put to MCStringStream using << syntax.
MCSerializer &	operator<< (MCSerializer &os, MCVariantType &vt)
	Alternative put to serializer using << syntax.

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Detailed Description

Base class for all variant data types.

Variants store any of the data types used by the rest of the library. There is no derived type to represent an undefined value. An undefined value means an empty variant was constructed and not assigned to. Undefined values equates to unset or null in other languages. Variants are typically used in the interface to systems where many different types of data can be transferred over the API boundary and the developer does not know in advance which type of data will be returned (example Database API, SNMP API)

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Constructor & Destructor Documentation

MCVariantType (   )

Default constructor. Creates a undefined value

~MCVariantType (   )

Destructor. Clean up the implementation.

MCVariantType (  const MCVariantType &  vt  )

Copy constructor. If the target variant type cannot accept values of the source variant type then an exception is thrown.

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Member Function Documentation

mcuint32 getTypeId (  const char *  typeName  )  [static]

Obtain the type id for a type name. Parameters: typeName  the type name to obtain a type id for. If typeName is not a registered type an exception is thrown. Returns: the type id for the type name.

mcuint32 getTypeId (   )  const

Obtain the internal type identifier for the variant. ALl variants of the same type have the same type identifier. The type ids are used to distinguish between the various types. Returns: the type id of the variant.

const MCString& getTypeName (  mcuint32  typeId  )  [static]

Get the type name of a type id. Parameters: typeId  the typeId to obtain the type name for Returns: the type name for the type id

const MCString& getTypeName (   )  const

Get the name of the type of this variant. Returns: the type name of the variant

bool isDefined (   )  const

Determine if the variant value is undefined. All derived classes construct defined values. Only the MCVariantType() constructor will construct an undefined value. Returns: true if the value does not represent undefined.

operator bool (   )  const

Determine if the variant value can be considered true. Every value of the standard variant types returns true except for the following:- undefined values empty strings zero numeric values false boolean values Returns: true if the value of the variant can be considered "true".

bool operator< (  const MCVariantType &  vt  )  const

Test if this variant type is less than another. Parameters: vt  the variant to compare Returns: true if this variant is less than to the other

MCVariantType& operator= (  const MCVariantType &  vt  )

Assigment. If the target variant type cannot accept values of the source variant type then an exception is thrown.

bool operator== (  const MCVariantType &  vt  )  const

Test if this variant type is equal to another. Parameters: vt  the variant to compare Returns: true if this variant is equal to the other

MCVariantType parse (  const MCString &  val  )  [static]

Parse a string and return a variant object for that string If the string is an empty string, or the special string "null" (excluding quotes and irrespective of case), an undefined variant value is returned. If the string is an integer value (as determined by strtol()) with no trailing characters, a MCVTInt64 variant value is returned. If the string is a float value (as determined by strtod()) with no trailing characters, a MCVTFloat64 variant value is returned. If the string is the special strings "true" or "false" (excluding quotes and irrespective of case), the corresponding MCVTBool variant value is returned. Otherwise an MCVTString variant value is returned. Parameters: val  the string to obtain an variant for Returns: the variant corresponding to the given string

void put (  MCStringStream &  os  )  const

Put to a string stream. The contained data is converted to a string representation when it is put to a string stream. Parameters: os  the MCStringStream to put the data to

void put (  MCSerializer &  serializer  )  const

Put to a serializer (serialize it). Parameters: serializer  the serializer to serialize the contained data to

MCString toString (   )  const

Get a string representation of the value. To get greater control (e.g. over numeric output format) put the variant to an ostream after putting suitable IO manipulators to the ostream Returns: a string representation of the variant using default formatting for the contained data

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