Class SBCMetaValueHolder#

template <typename T>

This template class describes a value holder. More...

#include <SBCMetaValueHolder.hpp>

Inherits the following classes: SBCMetaValueType

Inherited by the following classes: SBCClassObjectHolder

Public Functions#

Type	Name
	SBCMetaValueHolder (const T & v) Constructs a value holder that holds value `v` .
virtual SBCMetaValueBase *	clone () const Clones the value.
T const &	getConstReference () const Returns a const reference to the hold value.
T &	getReference () Returns a reference to the hold value.
T	getValue () const Returns the hold value.
virtual	~SBCMetaValueHolder () Destructs the value holder.

Public Functions inherited from SBCMetaValueType#

See SBCMetaValueType

Type	Name
	SBCMetaValueType () Constructs a type.
virtual SBCMetaValueBase *	clone () const Clones the value.
virtual SBCMetaValueBase *	getBaseType () const Returns the base type.
virtual std::string	getBaseTypeName () const Returns the base type name.
virtual SBCMetaValueBase *	getClassType () const Returns the class type.
virtual std::string	getClassTypeName () const Returns the class type name.
virtual unsigned int	getNumberOfParameters () const Returns the number of parameters of a function type.
virtual SBCMetaValueBase *	getOutputType () const Returns the output type.
virtual std::string	getOutputTypeName () const Returns the output type name.
virtual SBCMetaValueBase *	getParameterType (unsigned int i) const Returns the type of parameter `i` .
virtual std::string	getParameterTypeName (unsigned int i) const Returns the type name of parameter `i` .
virtual SBCMetaValueBase *	getParentType () const Returns the parent type.
virtual std::string	getParentTypeName () const Returns the parent type name.
virtual SBCMetaValueBase *	getRootType () const Returns the root type.
virtual std::string	getRootTypeName () const Returns the root type name.
virtual std::string	getShortBaseTypeName () const Returns the short base type name.
virtual std::string	getShortClassTypeName () const Returns the short class type name.
virtual std::string	getShortOutputTypeName () const Returns the short output type name.
virtual std::string	getShortParameterTypeName (unsigned int i) const Returns the short type name of parameter `i` .
virtual std::string	getShortParentTypeName () const Returns the short parent type name.
virtual std::string	getShortRootTypeName () const Returns the short root type name.
virtual std::string	getShortTypeName () const Returns the short type name.
virtual std::string	getTypeName () const Returns the type name.
virtual SBCContainerUUID	getTypeUUID () const Returns the type UUID .
virtual bool	hasBaseType () const Returns true if the value is of a type that has a base type.
virtual bool	isArrayType () const Returns true if the value is of an array type.
virtual bool	isClassType () const Returns true if the value is of a class type.
virtual bool	isConstType () const Returns true if the value is of a const type.
virtual bool	isEnumType () const Returns true if the value is of an enum type.
virtual bool	isFunctionType () const Returns true if the value is of a function type.
virtual bool	isFundamentalType () const Returns true if the value is of a fundamental type.
virtual bool	isPointerToFunctionType () const Returns true if the value is of a pointer to function type.
virtual bool	isPointerToMemberFunctionType () const Returns true if the value is of a pointer to member function type.
virtual bool	isPointerToMemberType () const Returns true if the value is of a pointer to member type.
virtual bool	isPointerType () const Returns true if the value is of a pointer type.
virtual bool	isReferenceType () const Returns true if the value is of a reference type.
virtual bool	isRegisteredType () const Returns true if the value is of a registered type.
virtual bool	isVolatileType () const Returns true if the value is of a volatile type.
virtual	~SBCMetaValueType () Destructs the type.

Public Functions inherited from SBCMetaValueBase#

See SBCMetaValueBase

Type	Name
virtual SBCMetaValueBase *	call (const SBCMetaValue & object, const std::string & functionName, const SBCMetaValue & t0, const SBCMetaValue & t1, const SBCMetaValue & t2, const SBCMetaValue & t3, const SBCMetaValue & t4, const SBCMetaValue & t5, const SBCMetaValue & t6, const SBCMetaValue & t7, const SBCMetaValue & t8, const SBCMetaValue & t9, const SBCMetaValue & t10, const SBCMetaValue & t11, const SBCMetaValue & t12, const SBCMetaValue & t13, const SBCMetaValue & t14, const SBCMetaValue & t15) const Calls the function `functionName` of the value with arguments`t0` ,`t1` , ...,`t15` .
virtual void	clear (const SBCMetaValue & object, const std::string & attributeName) const Clears attribute `attributeName` from the value when possible.
virtual SBCMetaValueBase *	clone () const Clones the value.
virtual SBCMetaValueBase *	constCall (const SBCMetaValue & object, const std::string & functionName, const SBCMetaValue & t0, const SBCMetaValue & t1, const SBCMetaValue & t2, const SBCMetaValue & t3, const SBCMetaValue & t4, const SBCMetaValue & t5, const SBCMetaValue & t6, const SBCMetaValue & t7, const SBCMetaValue & t8, const SBCMetaValue & t9, const SBCMetaValue & t10, const SBCMetaValue & t11, const SBCMetaValue & t12, const SBCMetaValue & t13, const SBCMetaValue & t14, const SBCMetaValue & t15) const Calls the const function `functionName` of the value with arguments`t0` ,`t1` , ...,`t15` .
virtual SBCMetaValueBase *	get (const SBCMetaValue & object, const std::string & attributeName) const Returns the value of attribute `attributeName` for this value.
virtual SBCMetaValueBase *	getBaseType () const Returns the base type.
virtual std::string	getBaseTypeName () const Returns the base type name.
virtual SBCMetaValueBase *	getClassType () const Returns the class type.
virtual std::string	getClassTypeName () const Returns the class type name.
virtual unsigned int	getNumberOfParameters () const Returns the number of parameters of a function type.
virtual SBCMetaValueBase *	getOutputType () const Returns the output type.
virtual std::string	getOutputTypeName () const Returns the output type name.
virtual SBCMetaValueBase *	getParameterType (unsigned int i) const Returns the type of parameter `i` .
virtual std::string	getParameterTypeName (unsigned int i) const Returns the type name of parameter `i` .
virtual SBCMetaValueBase *	getParentType () const Returns the parent type.
virtual std::string	getParentTypeName () const Returns the parent type name.
virtual SBCClassProxy *	getProxy () const Returns the proxy of the value.
virtual SBCMetaValueBase *	getRootType () const Returns the root type.
virtual std::string	getRootTypeName () const Returns the root type name.
virtual std::string	getShortBaseTypeName () const Returns the short base type name.
virtual std::string	getShortClassTypeName () const Returns the short class type name.
virtual std::string	getShortOutputTypeName () const Returns the short output type name.
virtual std::string	getShortParameterTypeName (unsigned int i) const Returns the short type name of parameter `i` .
virtual std::string	getShortParentTypeName () const Returns the short parent type name.
virtual std::string	getShortRootTypeName () const Returns the short root type name.
virtual std::string	getShortTypeName () const Returns the short type name.
virtual unsigned int	getSize (const SBCMetaValue & object, const std::string & attributeName) const Returns the size of attribute `attributeName` in the value when relevant.
virtual std::string	getTypeName () const Returns the type name.
virtual SBCContainerUUID	getTypeUUID () const Returns the type UUID .
virtual bool	has (const SBCMetaValue & object, const std::string & attributeName) const Returns whether attribute `attributeName` exists in the value and has a value.
virtual bool	hasBaseType () const Returns true if the value is of a type that has a base type.
virtual bool	isArrayType () const Returns true if the value is of an array type.
virtual bool	isClassType () const Returns true if the value is of a class type.
virtual bool	isConstType () const Returns true if the value is of a const type.
virtual bool	isEnumType () const Returns true if the value is of an enum type.
virtual bool	isFunctionType () const Returns true if the value is of a function type.
virtual bool	isFundamentalType () const Returns true if the value is of a fundamental type.
virtual bool	isPointerToFunctionType () const Returns true if the value is of a pointer to function type.
virtual bool	isPointerToMemberFunctionType () const Returns true if the value is of a pointer to member function type.
virtual bool	isPointerToMemberType () const Returns true if the value is of a pointer to member type.
virtual bool	isPointerType () const Returns true if the value is of a pointer type.
virtual bool	isReferenceType () const Returns true if the value is of a reference type.
virtual bool	isRegisteredType () const Returns true if the value is of a registered type.
virtual bool	isVolatileType () const Returns true if the value is of a volatile type.
virtual void	set (const SBCMetaValue & object, const std::string & attributeName, const SBCMetaValue & value, const SBCMetaValue & size) const Sets the value of attribute `attributeName` for this value to`value` .
virtual	~SBCMetaValueBase () Destructs the value.

Public Static Functions#

Type	Name
T const &	getValue (SBCMetaValueBase * container) Returns the value held in the `container` .

Protected Attributes#

Type	Name
T	value The hold value.

Protected Functions inherited from SBCMetaValueBase#

See SBCMetaValueBase

Type	Name
	SBCMetaValueBase () Constructs a value.

Detailed Description#

Parameters:

T The type described

This template class holds a value. It derives from the template class SBCMetaValueType, used to hold type information, which derives from SBCMetaValue, the base class of value holders.

Assume a SAMSON Extension called SEElement defines a class A, and another Extension called SEOtherElement wants to use it. If the Extension called SEOtherElement does not have access to the declaration of class A (typically provided in a header file included in SEElement), it cannot use the symbol A in its source code. For example, if the source code of SEOtherElement contained the line:

A* a = new A();

the compiler would complain that the symbol A is not defined.

In order to provide access to exposed classes, SAMSON uses a mechanism to hold values (for example, pointers to objects) in a uniform way. In the example above, the constructor exposed in the Extension SEElement returns a value holder that stores a pointer to the new instance of class A:

return new SBValueHolder<A*>(new A());

and the Extension SEOtherElement sees this value holder as a pointer to a SBValue (the base class of SBValueHolder<A*>):

SBValue* objectHolder = classProxy->createInstance();

Unlike the template class SBCMetaValueType, which only holds information about the type T of the value, the template class SBCMetaValueHolder does hold the value:

SBValueHolder<int>* intHolder = new SBValueHolder<int>(2);
int i = intHolder->getValue(); // i = 2
std::string typeName = intHolder->getTypeName(); // typeName = "int"

Short name: SBValueHolder

See also: Introspection

Public Functions Documentation#

function SBCMetaValueHolder#

Constructs a value holder that holds value v .

inline SBCMetaValueHolder::SBCMetaValueHolder (
    const T & v
)

function clone#

Clones the value.

inline virtual SBCMetaValueBase * SBCMetaValueHolder::clone () const

Implements SBCMetaValueType::clone

function getConstReference#

Returns a const reference to the hold value.

inline T const & SBCMetaValueHolder::getConstReference () const

function getReference#

Returns a reference to the hold value.

inline T & SBCMetaValueHolder::getReference ()

function getValue [1/2]#

Returns the hold value.

inline T SBCMetaValueHolder::getValue () const

function ~SBCMetaValueHolder#

Destructs the value holder.

inline virtual SBCMetaValueHolder::~SBCMetaValueHolder ()

Public Static Functions Documentation#

function getValue [2/2]#

Returns the value held in the container .

static inline T const & SBCMetaValueHolder::getValue (
    SBCMetaValueBase * container
)

Protected Attributes Documentation#

variable value#

The hold value.

T value;