eagine::valtree::compound_attribute Class Reference

Combination of a reference to a tree compound and a single attribute. More...

#include <eagine/value_tree/wrappers.hpp>

Public Member Functions
	compound_attribute () noexcept=default
	Default constructor. Constructs empty attribute refering to nothing.
	compound_attribute (compound c, attribute a) noexcept
	Construction from a compound and attribute pair. More...
	operator bool () const noexcept
	Indicates if this attribute actually refers to something.
auto	type_id () const noexcept
	Returns the shared implementation type id of the attribute and compound.
auto	name () const noexcept -> string_view
	Returns the name of this attribute.
auto	is_link () const noexcept -> bool
	Indicates if the specified attribute is a reference or link in the tree.
auto	canonical_type () const -> value_type
	Returns the canonical value type of this attribute.
auto	nested_count () const -> span_size_t
	Returns the count of nested attributes of an attribute. More...
auto	has_nested () const -> span_size_t
	Indicates if an attribute has nested attribute accessible by index.
auto	nested (span_size_t index) const -> compound_attribute
	Returns nested attribute of an attribute at the specified index. More...
auto	nested (string_view name) const -> compound_attribute
	Returns nested attribute of an attribute with the specified name. More...
auto	find (const basic_string_path &path) const -> compound_attribute
	Returns nested attribute of an attribute at the specified path. More...
auto	value_count () const -> span_size_t
	Returns the number of value elements accessible through an attribute.
template<typename T >
auto	fetch_values (span_size_t offset, span< T > dest) const
	Fetches values from this attribute, starting at offset, into dest.
template<typename T >
auto	fetch_values (span< T > dest) const
	Fetches values from this attribute, into dest.
auto	fetch_blob (memory::block dest) const
	Fetches a BLOB from this attribute, into dest.
template<typename T , identifier_t V>
auto	fetch_value (span_size_t offset, T &dest, selector< V > sel=default_selector) const -> bool
	Fetches a value from this attribute, starting at offset, with selector.
template<typename T , identifier_t V>
auto	select_value (T &dest, selector< V > sel) const -> bool
	Fetches a value from this attribute, with selector.
template<typename T , identifier_t V>
auto	select_values (span< T > dest, selector< V > sel) const -> span< T >
	Fetches a value from this attribute, with selector, into dest.
template<typename T >
auto	fetch_value (T &dest) const -> bool
	Fetches a value from this attribute, into dest.
template<typename T >
auto	get (span_size_t offset, type_identity< T > tid={}) const
	Returns a value of type T, from this attribute, at offset.
template<typename T >
auto	get (type_identity< T > tid={}) const
	Returns a value of type T, from this attribute.

Detailed Description

Combination of a reference to a tree compound and a single attribute.

This class provides a more convenient value tree access interface, at the cost of storage space.

Constructor & Destructor Documentation

compound_attribute()

eagine::valtree::compound_attribute::compound_attribute ( compound  c, attribute  a  )

inlinenoexcept

Construction from a compound and attribute pair.

Precondition

c.type_id() == a.type_id()

Member Function Documentation

find()

auto eagine::valtree::compound_attribute::find ( const basic_string_path &  path ) const -> compound_attribute

inline

Returns nested attribute of an attribute at the specified path.

Returns empty attribute handle if no such nested attribute exists.

nested() [1/2]

auto eagine::valtree::compound_attribute::nested ( span_size_t  index ) const -> compound_attribute

inline

Returns nested attribute of an attribute at the specified index.

Returns empty attribute handle if no such nested attribute exists.

nested() [2/2]

auto eagine::valtree::compound_attribute::nested ( string_view  name ) const -> compound_attribute

inline

Returns nested attribute of an attribute with the specified name.

Returns empty attribute handle if no such nested attribute exists.

nested_count()

auto eagine::valtree::compound_attribute::nested_count ( ) const -> span_size_t

inline

Returns the count of nested attributes of an attribute.

Note

Some implementations may return zero here even if there are nested attributes. In such implementations the nested nodes can be traversed only by name.

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

• eagine/value_tree/wrappers.hpp