nt::StructSubscriber< T, I > Class Template Reference

NetworkTables struct-encoded value subscriber. More...

#include <networktables/StructTopic.h>

Inheritance diagram for nt::StructSubscriber< T, I >:

Public Types
using	TopicType = StructTopic< T, I... >
using	ValueType = T
using	ParamType = const T &
using	TimestampedValueType = Timestamped< T >

Public Member Functions
	StructSubscriber ()=default
	StructSubscriber (NT_Subscriber handle, T defaultValue, I... info)
	Construct from a subscriber handle; recommended to use StructTopic::Subscribe() instead. More...
ValueType	Get () const
	Get the last published value. More...
ValueType	Get (const T &defaultValue) const
	Get the last published value. More...
bool	GetInto (T *out)
	Get the last published value, replacing the contents in place of an existing object. More...
TimestampedValueType	GetAtomic () const
	Get the last published value along with its timestamp If no value has been published or the value cannot be unpacked, returns the stored default value and a timestamp of 0. More...
TimestampedValueType	GetAtomic (const T &defaultValue) const
	Get the last published value along with its timestamp. More...
std::vector< TimestampedValueType >	ReadQueue ()
	Get an array of all valid value changes since the last call to ReadQueue. More...
TopicType	GetTopic () const
	Get the corresponding topic. More...
Public Member Functions inherited from nt::Subscriber
virtual	~Subscriber ()
	Subscriber (const Subscriber &)=delete
Subscriber &	operator= (const Subscriber &)=delete
	Subscriber (Subscriber &&)
Subscriber &	operator= (Subscriber &&)
	operator bool () const
	Determines if the native handle is valid. More...
NT_Subscriber	GetHandle () const
	Gets the native handle for the subscriber. More...
bool	Exists () const
	Determines if the topic is currently being published. More...
int64_t	GetLastChange () const
	Gets the last time the value was changed. More...
Topic	GetTopic () const
	Gets the subscribed-to topic. More...

Additional Inherited Members
Protected Member Functions inherited from nt::Subscriber
	Subscriber ()=default
	Subscriber (NT_Subscriber handle)
Protected Attributes inherited from nt::Subscriber
NT_Subscriber	m_subHandle {0}

Detailed Description

template<typename T, typename... I>
requires wpi::StructSerializable<T, I...>
class nt::StructSubscriber< T, I >

NetworkTables struct-encoded value subscriber.

Member Typedef Documentation

ParamType

template<typename T , typename... I>

using nt::StructSubscriber< T, I >::ParamType = const T&

TimestampedValueType

template<typename T , typename... I>

using nt::StructSubscriber< T, I >::TimestampedValueType = Timestamped<T>

TopicType

template<typename T , typename... I>

using nt::StructSubscriber< T, I >::TopicType = StructTopic<T, I...>

ValueType

template<typename T , typename... I>

using nt::StructSubscriber< T, I >::ValueType = T

Constructor & Destructor Documentation

StructSubscriber() [1/2]

template<typename T , typename... I>

nt::StructSubscriber< T, I >::StructSubscriber ( )

default

StructSubscriber() [2/2]

template<typename T , typename... I>

nt::StructSubscriber< T, I >::StructSubscriber ( NT_Subscriber  handle, T  defaultValue, I...  info  )

inline

Construct from a subscriber handle; recommended to use StructTopic::Subscribe() instead.

Parameters

handle	Native handle
defaultValue	Default value
info	optional struct type info

Member Function Documentation

Get() [1/2]

template<typename T , typename... I>

ValueType nt::StructSubscriber< T, I >::Get ( ) const

inline

Get the last published value.

If no value has been published or the value cannot be unpacked, returns the stored default value.

Returns

value

Get() [2/2]

template<typename T , typename... I>

ValueType nt::StructSubscriber< T, I >::Get ( const T &  defaultValue ) const

inline

Get the last published value.

If no value has been published or the value cannot be unpacked, returns the passed defaultValue.

Parameters

defaultValue

default value to return if no value has been published

Returns

value

GetAtomic() [1/2]

template<typename T , typename... I>

TimestampedValueType nt::StructSubscriber< T, I >::GetAtomic ( ) const

inline

Get the last published value along with its timestamp If no value has been published or the value cannot be unpacked, returns the stored default value and a timestamp of 0.

Returns

timestamped value

GetAtomic() [2/2]

template<typename T , typename... I>

TimestampedValueType nt::StructSubscriber< T, I >::GetAtomic ( const T &  defaultValue ) const

inline

Get the last published value along with its timestamp.

If no value has been published or the value cannot be unpacked, returns the passed defaultValue and a timestamp of 0.

Parameters

defaultValue

default value to return if no value has been published

Returns

timestamped value

GetInto()

template<typename T , typename... I>

bool nt::StructSubscriber< T, I >::GetInto ( T *  out )

inline

Get the last published value, replacing the contents in place of an existing object.

If no value has been published or the value cannot be unpacked, does not replace the contents and returns false.

Parameters

[out]

out

object to replace contents of

Returns

true if successful

GetTopic()

template<typename T , typename... I>

TopicType nt::StructSubscriber< T, I >::GetTopic ( ) const

inline

Get the corresponding topic.

Returns

Topic

ReadQueue()

template<typename T , typename... I>

std::vector< TimestampedValueType > nt::StructSubscriber< T, I >::ReadQueue ( )

inline

Get an array of all valid value changes since the last call to ReadQueue.

Also provides a timestamp for each value. Values that cannot be unpacked are dropped.

Note

The "poll storage" subscribe option can be used to set the queue depth.

Returns

Array of timestamped values; empty array if no valid new changes have been published since the previous call.

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

• networktables/StructTopic.h