Generic Values A polymorphic type that can hold values of any other type The #GValue structure is basically a variable container that consists of a type identifier and a specific value of that type. The type identifier within a #GValue structure always determines the type of the associated value. To create a undefined #GValue structure, simply create a zero-filled #GValue structure. To initialize the #GValue, use the g_value_init() function. A #GValue cannot be used until it is initialized. The basic type operations (such as freeing and copying) are determined by the #GTypeValueTable associated with the type ID stored in the #GValue. Other #GValue operations (such as converting values between types) are provided by this interface. The fundamental types which all support #GValue operations and thus can be used as a type initializer for g_value_init() are defined by a separate interface. See the Standard Values API for details. Returns %TRUE if @value holds (or contains) a value of @type. This macro will also check for @value != %NULL and issue a warning if the check fails. @value: A #GValue structure. @type: A #GType value. Returns the type identifier of @value. @value: A #GValue structure. Returns the type name of @value. @value: A #GValue structure. Return whether the passed in type ID can be used for g_value_init(). That is, this macro checks whether this type provides an implementation of the #GTypeValueTable functions required for a type to create a #GValue of. @type: A #GType value. @Returns: Whether @type is suitable as a #GValue type. Returns %TRUE if @type is an abstract value type. An abstract value type introduces a value table, but can't be used for g_value_init() and is normally used as an abstract base type for derived value types. @type: A #GType value. Returns %TRUE if @value is a valid and initialized #GValue structure. @value: A #GValue structure. An opaque structure used to hold different types of values. The data within the structure has protected scope: it is accessible only to functions within a #GTypeValueTable structure, or implementations of the g_value_*() API. That is, code portions which implement new fundamental types. #GValue users can not make any assumptions about how data is stored within the 2 element @data union, and the @g_type member should only be accessed through the G_VALUE_TYPE() macro. Returns the type ID of the "GValue" type which is a boxed type, used to pass around pointers to GValues. Returns the type ID of the "GValueArray" type which is a boxed type, used to pass around pointers to GValueArrays. Initializes @value with the default value of @type. @value: A zero-filled (uninitialized) #GValue structure. @g_type: Type the #GValue should hold values of. @Returns: the #GValue structure that has been passed in Copies the value of @src_value into @dest_value. @src_value: An initialized #GValue structure. @dest_value: An initialized #GValue structure of the same type as @src_value. Clears the current value in @value and resets it to the default value (as if the value had just been initialized). @value: An initialized #GValue structure. @Returns: the #GValue structure that has been passed in Clears the current value in @value and "unsets" the type, this releases all resources associated with this GValue. An unset value is the same as an uninitialized (zero-filled) #GValue structure. @value: An initialized #GValue structure. Sets @value from an instantiatable type via the value_table's collect_value() function. @value: An initialized #GValue structure. @instance: the instance Determines if @value will fit inside the size of a pointer value. This is an internal function introduced mainly for C marshallers. @value: An initialized #GValue structure. @Returns: %TRUE if @value will fit inside a pointer value. Return the value contents as pointer. This function asserts that g_value_fits_pointer() returned %TRUE for the passed in value. This is an internal function introduced mainly for C marshallers. @value: An initialized #GValue structure. @Returns: %TRUE if @value will fit inside a pointer value. Returns whether a #GValue of type @src_type can be copied into a #GValue of type @dest_type. @src_type: source type to be copied. @dest_type: destination type for copying. @Returns: %TRUE if g_value_copy() is possible with @src_type and @dest_type. Check whether g_value_transform() is able to transform values of type @src_type into values of type @dest_type. @src_type: Source type. @dest_type: Target type. @Returns: %TRUE if the transformation is possible, %FALSE otherwise. Tries to cast the contents of @src_value into a type appropriate to store in @dest_value, e.g. to transform a %G_TYPE_INT value into a %G_TYPE_FLOAT value. Performing transformations between value types might incur precision lossage. Especially transformations into strings might reveal seemingly arbitrary results and shouldn't be relied upon for production code (such as rcfile value or object property serialization). @src_value: Source value. @dest_value: Target value. @Returns: Whether a transformation rule was found and could be applied. Upon failing transformations, @dest_value is left untouched. The type of value transformation functions which can be registered with g_value_register_transform_func(). @src_value: Source value. @dest_value: Target value. Registers a value transformation function for use in g_value_transform(). A previously registered transformation function for @src_type and @dest_type will be replaced. @src_type: Source type. @dest_type: Target type. @transform_func: a function which transforms values of type @src_type into value of type @dest_type Return a newly allocated string, which describes the contents of a #GValue. The main purpose of this function is to describe #GValue contents for debugging output, the way in which the contents are described may change between different GLib versions. @value: #GValue which contents are to be described. @Returns: Newly allocated string.