glibmm
2.33.3
|
The base class from which multiple-item Variants derive, such as Variants containing tuples or arrays. More...
#include <glibmm/variant.h>
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. |
The base class from which multiple-item Variants derive, such as Variants containing tuples or arrays.
typedef GVariant* Glib::VariantContainerBase::CType |
Reimplemented in Glib::Variant< VariantBase >.
Glib::VariantContainerBase::VariantContainerBase | ( | ) |
Default constructor.
Glib::VariantContainerBase::VariantContainerBase | ( | GVariant * | castitem, |
bool | take_a_reference = false |
||
) | [explicit] |
GVariant constructor.
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). |
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.
child_type | The VariantType of the child, or 0 . |
child | The child value, or 0 . |
static VariantContainerBase Glib::VariantContainerBase::create_tuple | ( | const std::vector< VariantBase >& | children | ) | [static] |
Create a tuple variant from a vector of its variant children.
children | The vector containing the children of the container. |
static VariantContainerBase Glib::VariantContainerBase::create_tuple | ( | const VariantBase& | child | ) | [static] |
Create a tuple variant with a single variant child.
child | The child variant. |
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).
index | The index of the child to fetch. |
child | A location in which to store the child at the specified index. |
std::out_of_range |
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).
index | The index of the child to fetch. |
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
.
maybe | A place in which to return the value (the value may be 0 ). |
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).