dds::core::optional< T > Class Template Reference

#include "Optional.hpp"

Inherits dds::core::Value< D >.

Public Member Functions
	optional (const T &t)
T &	get ()
const T &	get () const
bool	is_set () const
bool	operator!= (const Value &other) const
D *	operator-> ()
const D *	operator-> () const
bool	operator== (const Value &other) const
void	reset ()

Detailed Description

template<typename T>
class dds::core::optional< T >

The optional class is used to wrap attributes annotated in the idl with the @optional annotation. This class provides a simple and safe way of accessing, setting and resetting the stored attribute.

IDL:

struct RadarTrack {
    string id;
    long x;
    long y;
    long z; //@Optional
};

C++ Representation:

class RadarTrack {
public:
    RadarTrack();
    RadarTrack(const std::string& id,
               int32_t x,
               int32_t y,
               int32_t z);
public:
    std::string& id() const;
    void id(const std::string& s);
 
    int32_t x() const;
    void x(int32_t v);
 
    int32_t y() const;
    void y(int32_t v);
 
    dds::core::optional<int32_t>& z() const;
    void z(int32_t v);
    void z(const dds::core::optional<int32_t>& z)
};

Definition at line 69 of file Optional.hpp.

Constructor & Destructor Documentation

optional()

template<typename T>

dds::core::optional< T >::optional

(

const T &

t

)

Member Function Documentation

get() [1/2]

template<typename T>

T& dds::core::optional< T >::get

(

)

Get the attribute. An exception is thrown if the attribute is not set.

get() [2/2]

template<typename T>

const T& dds::core::optional< T >::get

(

)

const

Get the attribute. An exception is thrown if the attribute is not set.

is_set()

template<typename T>

bool dds::core::optional< T >::is_set

(

)

const

Returns true only if the attribute is set.

operator!=()

template<typename D >

bool dds::core::Value< D >::operator!= ( const Value< D > &  other ) const

inherited

Compare this Value with another Value

Parameters

other

Value

Returns

true if not equal

operator->() [1/2]

template<typename D >

D* dds::core::Value< D >::operator-> ( )

inherited

The operator->() is provided to be able to directly invoke functions on the delegate.

The decision to provide direct access to the delegate was motivated by the need for providing a way that was not invasive with respect to the CXXDDS API and yet would allow for vendor-specific extension. Thus vendor-specific extensions can be invoked on the Value and on all its subclasses as follows:

my_dds_value.standard_function();
my_dds_value->vendor_specific_extension();

Returns

a reference to delegate.

operator->() [2/2]

template<typename D >

const D* dds::core::Value< D >::operator-> ( ) const

inherited

The operator->() is provided to be able to directly invoke functions on the delegate.

The decision to provide direct access to the delegate was motivated by the need for providing a way that was not invasive with respect to the CXXDDS API and yet would allow for vendor-specific extension. Thus vendor-specific extensions can be invoked on the Value and on all its subclasses as follows:

my_dds_value.standard_function();
my_dds_value->vendor_specific_extension();

Returns

a reference to delegate.

operator==()

template<typename D >

bool dds::core::Value< D >::operator== ( const Value< D > &  other ) const

inherited

Compare this Value with another Value

Parameters

other

Value

Returns

true if equal

reset()

template<typename T>

void dds::core::optional< T >::reset

(

)

Reset the attribute.

---

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

• dds/core/Optional.hpp