ROOT::Experimental::RNTupleView< T > Class Template Reference

template<typename T>
class ROOT::Experimental::RNTupleView< T >

An RNTupleView provides read-only access to a single field of the ntuple.

(NB(jblomer): The ntuple view is very close to TTreeReader. Do we simply want to teach TTreeReader to deal with RNTuple?)

The view owns a field and its underlying columns in order to fill an ntuple value object with data. Data can be accessed by index. For top level fields, the index refers to the entry number. Fields that are part of nested collections have global index numbers that are derived from their parent indexes.

The RNTupleView object is an iterable. That means, all field values in the tree can be sequentially read from begin() to end().

For simple types, template specializations let the reading become a pure mapping into a page buffer.

Definition at line 86 of file RNTupleView.hxx.

Public Member Functions
	RNTupleView (const RNTupleView &other)=delete
	RNTupleView (RNTupleView &&other)=default
	~RNTupleView ()
const T &	operator() (NTupleSize_t index)
RNTupleView &	operator= (const RNTupleView &other)=delete
RNTupleView &	operator= (RNTupleView &&other)=default

Protected Member Functions
	RNTupleView (std::string_view fieldName, Detail::RPageSource *pageSource)

Protected Attributes
RField< T >	fField
Detail::RFieldValue	fValue

Friends
class	RNTupleReader
class	RNTupleViewCollection

#include <ROOT/RNTupleView.hxx>

Constructor & Destructor Documentation

RNTupleView() [1/3]

template<typename T >

ROOT::Experimental::RNTupleView< T >::RNTupleView ( std::string_view  fieldName, Detail::RPageSource *  pageSource  )

inlineprotected

Definition at line 93 of file RNTupleView.hxx.

RNTupleView() [2/3]

template<typename T >

ROOT::Experimental::RNTupleView< T >::RNTupleView ( const RNTupleView< T > &  other )

delete

RNTupleView() [3/3]

template<typename T >

ROOT::Experimental::RNTupleView< T >::RNTupleView ( RNTupleView< T > &&  other )

default

~RNTupleView()

template<typename T >

ROOT::Experimental::RNTupleView< T >::~RNTupleView ( )

inline

Definition at line 107 of file RNTupleView.hxx.

Member Function Documentation

operator()()

template<typename T >

const T & ROOT::Experimental::RNTupleView< T >::operator() ( NTupleSize_t  index )

inline

Definition at line 109 of file RNTupleView.hxx.

operator=() [1/2]

template<typename T >

RNTupleView & ROOT::Experimental::RNTupleView< T >::operator= ( const RNTupleView< T > &  other )

delete

operator=() [2/2]

template<typename T >

RNTupleView & ROOT::Experimental::RNTupleView< T >::operator= ( RNTupleView< T > &&  other )

default

Friends And Related Function Documentation

RNTupleReader

template<typename T >

friend class RNTupleReader

friend

Definition at line 87 of file RNTupleView.hxx.

RNTupleViewCollection

template<typename T >

friend class RNTupleViewCollection

friend

Definition at line 88 of file RNTupleView.hxx.

Member Data Documentation

fField

template<typename T >

RField<T> ROOT::Experimental::RNTupleView< T >::fField

protected

Definition at line 91 of file RNTupleView.hxx.

fValue

template<typename T >

Detail::RFieldValue ROOT::Experimental::RNTupleView< T >::fValue

protected

Definition at line 92 of file RNTupleView.hxx.

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

• tree/ntuple/v7/inc/ROOT/RNTupleView.hxx