The base class from which multiple-item Variants derive, such as Variants containing tuples or arrays. More...

#include <glibmm/variant.h>

Inheritance diagram for Glib::VariantContainerBase:

List of all members.

Public Types
typedef GVariant*	CType
typedef VariantContainerBase	CppType
Public Member Functions
	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.
bool	get_maybe (VariantBase& maybe) const
	If this is a maybe-typed instance, extract its value.
Static Public Member Functions
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=VariantBase())
	Depending on if child is 0, either wraps child inside of a maybe container or creates a Nothing instance for the given type.

---

Detailed Description

The base class from which multiple-item Variants derive, such as Variants containing tuples or arrays.

Since glibmm 2.28:

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Member Typedef Documentation

typedef VariantContainerBase Glib::VariantContainerBase::CppType

Reimplemented in Glib::Variant< std::map< K, V > >, Glib::Variant< std::vector< std::string > >, Glib::Variant< std::vector< Glib::ustring > >, Glib::Variant< std::vector< T > >, and Glib::Variant< VariantBase >.

typedef GVariant* Glib::VariantContainerBase::CType

Reimplemented in Glib::Variant< VariantBase >.

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Constructor & Destructor Documentation

Glib::VariantContainerBase::VariantContainerBase

(

)

Default constructor.

Glib::VariantContainerBase::VariantContainerBase	(	GVariant *	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).

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Member Function Documentation

static VariantContainerBase Glib::VariantContainerBase::create_maybe	(	const VariantType&	child_type,
		const VariantBase&	child = VariantBase()
	)		[static]

Depending on if child is 0, either wraps child inside of a maybe container or creates a Nothing instance for the given type.

At least one of child_type and child must be non-0. If child_type is non-0 then it must be a definite type. If they are both non-0 then child_type must be the type of child.

If child is a floating reference (see g_variant_ref_sink()), the new instance takes ownership of child.

Since glibmm 2.24:

Parameters:

child_type	The VariantType of the child, or 0.
child	The child value, or 0.

Returns:

A floating reference to a new Variant maybe instance.

static VariantContainerBase Glib::VariantContainerBase::create_tuple

(

const std::vector< VariantBase >&

children

)

[static]

Create a tuple variant from a vector of its variant children.

Parameters:

children

The vector containing the children of the container.

Returns:

The newly created tuple variant (as a VariantContainerBase).

static VariantContainerBase Glib::VariantContainerBase::create_tuple

(

const VariantBase&

child

)

[static]

Create a tuple variant with a single variant child.

Parameters:

child

The child variant.

Returns:

The newly created tuple variant (as a VariantContainerBase).

void Glib::VariantContainerBase::get_child	(	VariantBase&	child,
		gsize	index = 0
	)		const

Reads a child item out of this instance.

This method is valid for variants, maybes, arrays, tuples and dictionary entries.

It is an error if index is greater than the number of child items in the container. See get_n_children().

This function is O(1).

Parameters:

index	The index of the child to fetch.
child	A location in which to store the child at the specified index.

Exceptions:

std::out_of_range

Since glibmm 2.28:

VariantBase Glib::VariantContainerBase::get_child

(

gsize

index = 0

)

Reads a child item out of a container Variant instance.

This includes variants, maybes, arrays, tuples and dictionary entries. It is an error to call this function on any other type of Variant.

It is an error if index is greater than the number of child items in the container. See g_variant_n_children().

The returned value is never floating. You should free it with g_variant_unref() when you're done with it.

This function is O(1).

Since glibmm 2.24:

Parameters:

index

The index of the child to fetch.

Returns:

The child at the specified index.

bool Glib::VariantContainerBase::get_maybe

(

VariantBase&

maybe

)

const

If this is a maybe-typed instance, extract its value.

If the value is Nothing, then this function returns 0.

Parameters:

maybe

A place in which to return the value (the value may be 0).

Since glibmm 2.28:

gsize Glib::VariantContainerBase::get_n_children

(

)

const

Determines the number of children in a container Variant instance.

This includes variants, maybes, arrays, tuples and dictionary entries. It is an error to call this function on any other type of Variant.

For variants, the return value is always 1. For values with maybe types, it is always zero or one. For arrays, it is the length of the array. For tuples it is the number of tuple items (which depends only on the type). For dictionary entries, it is always 2

This function is O(1).

Since glibmm 2.24:

Returns:

The number of children in the container.