glibmm: Glib::Variant< VariantBase

Specialization of Variant containing a VariantBase. More...

#include <glibmm/variant.h>

Inheritance diagram for Glib::Variant< VariantBase >:

[legend]

Public Types
using	CType = GVariant *

using	CppType = VariantBase

using	CppContainerType = Variant< VariantBase >

Public Types inherited from Glib::VariantContainerBase
using	CType = GVariant *

using	CppType = VariantContainerBase

Public Member Functions
	Variant ()
	Default constructor.

	Variant (GVariant *castitem, bool take_a_reference=false)
	GVariant constructor.

void	get (VariantBase & variant) const

VariantBase	get () const
	Unboxes value.

Public Member Functions inherited from Glib::VariantContainerBase
	VariantContainerBase ()
	Default constructor.

	VariantContainerBase (GVariant *castitem, bool take_a_reference=false)
	GVariant constructor.

gsize	get_n_children () const
	Determines the number of children in a container Variant instance.

void	get_child (VariantBase &child, gsize index=0) const
	Reads a child item out of this instance.

VariantBase	get_child (gsize index=0)
	Reads a child item out of a container Variant instance.

VariantBase	get_child (gsize index=0) const
	Reads a child item out of a container Variant instance.

bool	get_maybe (VariantBase &maybe) const
	If this is a maybe-typed instance, try to extract its value.

Public Member Functions inherited from Glib::VariantBase
	VariantBase ()
	Constructs an invalid object.

	VariantBase (GVariant *castitem, bool make_a_copy=false)

	VariantBase (const VariantBase &src)

VariantBase &	operator= (const VariantBase &src)

	VariantBase (VariantBase &&other) noexcept

VariantBase &	operator= (VariantBase &&other) noexcept

	~VariantBase () noexcept

void	swap (VariantBase &other) noexcept

GVariant *	gobj ()

const GVariant *	gobj () const

GVariant *	gobj_copy () const
	Provides access to the underlying C instance. The caller is responsible for freeing it. Use when directly setting fields in structs.

	operator bool () const
	Test whether the Variant has an underlying instance.

void	init (const GVariant *cobject, bool take_a_reference=false)
	Replace the underlying GVariant.

VariantType	get_type () const
	Determines the type of value.

std::string	get_type_string () const
	Returns the type string of value.

bool	is_floating () const
	Checks whether value has a floating reference count.

bool	is_of_type (const VariantType & type) const
	Checks if a value has a type matching the provided type.

bool	is_container () const
	Checks if value is a container.

GVariantClass	classify () const
	Classifies value according to its top-level type.

gsize	get_size () const
	Determines the number of bytes that would be required to store value with g_variant_store().

gconstpointer	get_data () const
	Returns a pointer to the serialized form of a Variant instance.

Glib::RefPtr< const Glib::Bytes >	get_data_as_bytes () const
	Returns a pointer to the serialized form of a Variant instance.

void	store (gpointer data) const
	Stores the serialized form of value at data.

Glib::ustring	print (bool type_annotate=false) const
	Pretty-prints value in the format understood by g_variant_parse().

guint	hash () const
	Generates a hash value for a Variant instance.

bool	equal (const VariantBase &other) const
	Checks if this and other* have the same type and value.

bool	operator== (const VariantBase &other) const
	Checks if this and other* have the same type and value.

bool	operator!= (const VariantBase &other) const
	Checks if this and other* have the same type and value.

bool	operator< (const VariantBase &other) const =delete
	Ordering relational operators.

bool	operator<= (const VariantBase &other) const =delete
	See operator<().

bool	operator> (const VariantBase &other) const =delete
	See operator<().

bool	operator>= (const VariantBase &other) const =delete
	See operator<().

void	get_normal_form (VariantBase &result) const
	Gets a VariantBase instance that has the same value as this variant and is trusted to be in normal form.

bool	is_normal_form () const
	Checks if value is in normal form.

void	byteswap (VariantBase &result) const
	Performs a byteswapping operation on the contents of this variant.

bool	check_format_string (const std::string & format_string, bool copy_only=false) const
	Checks if calling g_variant_get() with format_string on value would be valid from a type-compatibility standpoint.

template<typename ValueType >
ValueType	get_dynamic () const
	Cast to a specific variant type and get the value.

Static Public Member Functions
static const VariantType &	variant_type ()
	Gets the VariantType.

static Variant< VariantBase >	create (const VariantBase &data)
	Creates a new Variant<VariantBase>.

Static Public Member Functions inherited from Glib::VariantContainerBase
static VariantContainerBase	create_tuple (const std::vector< VariantBase > &children)
	Create a tuple variant from a vector of its variant children.

static VariantContainerBase	create_tuple (const VariantBase &child)
	Create a tuple variant with a single variant child.

static VariantContainerBase	create_maybe (const VariantType &child_type, const VariantBase &child={})
	Depending on if child is `nullptr`, either wraps child inside of a maybe container or creates a Nothing instance for the given type.

Static Public Member Functions inherited from Glib::VariantBase
template<class V_CastTo >
static V_CastTo	cast_dynamic (const VariantBase &v)
	Cast to a specific variant type.

template<>
VariantContainerBase	cast_dynamic (const VariantBase &v)

Additional Inherited Members
Protected Attributes inherited from Glib::VariantBase
GVariant *	gobject_

Related Symbols inherited from Glib::VariantBase
template<typename T >
Variant< T >	create_variant (const T &data)
	Creates a Glib::Variant instance.

void	swap (VariantBase &lhs, VariantBase &rhs) noexcept

Glib::VariantBase	wrap (GVariant *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Detailed Description

Specialization of Variant containing a VariantBase.

Perhaps the main use of this is as a maybe-typed (i.e. nullable) Variant, as it inherits the methods create_maybe() and get_maybe() from VariantContainerBase, plus get_n_children() to allow checking whether there is a contained value, i.e. the inner Variant is not nothing.

Since glibmm 2.28:

Member Typedef Documentation

◆ CppContainerType

using Glib::Variant< VariantBase >::CppContainerType = Variant<VariantBase>

◆ CppType

using Glib::Variant< VariantBase >::CppType = VariantBase

◆ CType

using Glib::Variant< VariantBase >::CType = GVariant*

Constructor & Destructor Documentation

◆ Variant() [1/2]

Glib::Variant< VariantBase >::Variant ( )

Default constructor.

◆ Variant() [2/2]

Glib::Variant< VariantBase >::Variant	(	GVariant< VariantBase > *	castitem,
		bool	take_a_reference = `false`
	)

explicit

GVariant constructor.

Parameters

castitem	The GVariant to wrap.
take_a_reference	Whether to take an extra reference of the GVariant or not (not taking one could destroy the GVariant with the wrapper).

Member Function Documentation

◆ create()

static Variant< VariantBase > Glib::Variant< VariantBase >::create ( const VariantBase & data )

static

Creates a new Variant<VariantBase>.

Parameters

data	The value of the new Variant.

Returns: The new Variant.

Since glibmm 2.28:

◆ get() [1/2]

VariantBase Glib::Variant< VariantBase >::get ( ) const

Unboxes value.

The result is the Variant instance that was contained in value.

Since glibmm 2.24:

Returns: The item contained in the variant.

◆ get() [2/2]

void Glib::Variant< VariantBase >::get ( VariantBase & variant ) const

◆ variant_type()

static const VariantType & Glib::Variant< VariantBase >::variant_type ( )