Value

Object Hierarchy:

Description:

[ CCode ( copy_function = "g_value_copy" , destroy_function = "g_value_unset" , get_value_function = "g_value_get_boxed" , marshaller_type_name = "BOXED" , set_value_function = "g_value_set_boxed" , take_value_function = "g_value_take_boxed" , type_id = "G_TYPE_VALUE" , type_signature = "v" ) ]
public struct Value

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 TypeValueTable structure, or implementations of the g_value_*() API. That is, code portions which implement new fundamental types.

Value users cannot 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 type macro.

Example: GLib.Value and strings:

public static int main (string[] args) {
	Value value1 = Value (typeof (string));
	value1.set_string ("My string");

	// Output: ``My string``
	print ("%s\n", value1.get_string ());

	// Output: ``My string``
	print ("%s\n", value1.dup_string ());

	// Output: ``My string``
	print ("%s\n", (string) value1);

	// Output: ``My string 2``
	value1 = "My string 2";
	print ("%s\n", (string) value1);

	return 0;
}

valac --pkg gobject-2.0 GLib.Value.vala

Namespace: GLib

Package: gobject-2.0

Content:

Static methods:

public static void register_transform_func (Type src_type, Type dest_type, ValueTransform transform_func)
Registers a value transformation function for use in transform.
public static bool type_compatible (Type src_type, Type dest_type)
Returns whether a Value of type src_type can be copied into a Value of type dest_type.
public static bool type_transformable (Type src_type, Type dest_type)
Check whether transform is able to transform values of type src_type into values of type dest_type.

Creation methods:

public Value (Type g_type)
Initializes this with the default value of type.

Methods:

public void copy (ref Value dest_value)
Copies the value of this into dest_value.
public void* dup_boxed ()
Get the contents of a g_type_boxed derived Value.
public Object dup_object ()
Get the contents of a g_type_object derived Value, increasing its reference count.
public ParamSpec dup_param ()
Get the contents of a g_type_param Value, increasing its reference count.
public string dup_string ()
Get a copy the contents of a g_type_string Value.
public Variant? dup_variant ()
Get the contents of a variant Value, increasing its refcount.
public bool fits_pointer ()
Determines if this will fit inside the size of a pointer value.
public bool get_boolean ()
Get the contents of a g_type_boolean Value.
public void* get_boxed ()
Get the contents of a g_type_boxed derived Value.
public char get_char ()
Do not use this function; it is broken on platforms where the char type is unsigned, such as ARM and PowerPC.
public double get_double ()
Get the contents of a g_type_double Value.
public int get_enum ()
Get the contents of a g_type_enum Value.
public uint get_flags ()
Get the contents of a g_type_flags Value.
public float get_float ()
Get the contents of a g_type_float Value.
public Type get_gtype ()
Get the contents of a g_type_gtype Value.
public int get_int ()
Get the contents of a g_type_int Value.
public int64 get_int64 ()
Get the contents of a g_type_int64 Value.
public long get_long ()
Get the contents of a g_type_long Value.
public unowned Object get_object ()
Get the contents of a g_type_object derived Value.
public unowned ParamSpec get_param ()
Get the contents of a g_type_param Value.
public void* get_pointer ()
Get the contents of a pointer Value.
public int8 get_schar ()
Get the contents of a g_type_char Value.
public unowned string get_string ()
Get the contents of a g_type_string Value.
public uchar get_uchar ()
Get the contents of a g_type_uchar Value.
public uint get_uint ()
Get the contents of a g_type_uint Value.
public uint64 get_uint64 ()
Get the contents of a g_type_uint64 Value.
public ulong get_ulong ()
Get the contents of a g_type_ulong Value.
public Variant? get_variant ()
Get the contents of a variant Value.
public bool holds (Type type)
public unowned Value? init (Type g_type)
public void init_from_instance (void* instance)
Initializes and sets this from an instantiatable type via the value_table's collect_value function.
public void* peek_pointer ()
Returns the value contents as pointer.
public unowned Value? reset ()
Clears the current value in this and resets it to the default value (as if the value had just been initialized).
public void set_boolean (bool v_boolean)
Set the contents of a g_type_boolean Value to v_boolean.
public void set_boxed (void* v_boxed)
Set the contents of a g_type_boxed derived Value to v_boxed.
public void set_char (char v_char)
Set the contents of a g_type_char Value to v_char.
public void set_double (double v_double)
Set the contents of a g_type_double Value to v_double.
public void set_enum (int v_enum)
Set the contents of a g_type_enum Value to v_enum.
public void set_flags (uint v_flags)
Set the contents of a g_type_flags Value to v_flags.
public void set_float (float v_float)
Set the contents of a g_type_float Value to v_float.
public void set_gtype (Type v_gtype)
Set the contents of a g_type_gtype Value to v_gtype.
public void set_instance (void* instance)
Sets this from an instantiatable type via the value_table's collect_value function.
public void set_int (int v_int)
Set the contents of a g_type_int Value to v_int.
public void set_int64 (int64 v_int64)
Set the contents of a g_type_int64 Value to v_int64.
public void set_interned_string (string? v_string)
Set the contents of a g_type_string Value to v_string.
public void set_long (long v_long)
Set the contents of a g_type_long Value to v_long.
public void set_object (Object? v_object)
Set the contents of a g_type_object derived Value to v_object.
public void set_param (ParamSpec? param)
Set the contents of a g_type_param Value to param.
public void set_param_take_ownership (owned ParamSpec? param)
This is an internal function introduced mainly for C marshallers.
public void set_pointer (void* v_pointer)
Set the contents of a pointer Value to v_pointer.
public void set_schar (int8 v_char)
Set the contents of a g_type_char Value to v_char.
public void set_static_string (string? v_string)
Set the contents of a g_type_string Value to v_string.
public void set_string (string? v_string)
Set the contents of a g_type_string Value to a copy of v_string.
public void set_uchar (uchar v_uchar)
Set the contents of a g_type_uchar Value to v_uchar.
public void set_uint (uint v_uint)
Set the contents of a g_type_uint Value to v_uint.
public void set_uint64 (uint64 v_uint64)
Set the contents of a g_type_uint64 Value to v_uint64.
public void set_ulong (ulong v_ulong)
Set the contents of a g_type_ulong Value to v_ulong.
public void set_variant (Variant? variant)
Set the contents of a variant Value to variant.
public string strdup_contents ()
Return a newly allocated string, which describes the contents of a Value.
public void take_boxed (void* v_boxed)
Sets the contents of a g_type_boxed derived Value to v_boxed and takes over the ownership of the caller’s reference to v_boxed; the caller doesn’t have to unref it any more.
public void take_object (owned Object? v_object)
Sets the contents of a g_type_object derived Value to v_object and takes over the ownership of the caller’s reference to v_object; the caller doesn’t have to unref it any more (i.
public void take_param (owned ParamSpec? param)
Sets the contents of a g_type_param Value to param and takes over the ownership of the caller’s reference to param; the caller doesn’t have to unref it any more.
public void take_string (owned string? v_string)
Sets the contents of a g_type_string Value to v_string.
public void take_variant (owned Variant? variant)
Set the contents of a variant Value to variant, and takes over the ownership of the caller's reference to variant; the caller doesn't have to unref it any more (i.
public bool transform (ref Value dest_value)
Tries to cast the contents of this into a type appropriate to store in dest_value, e.
public Type type ()
public unowned string type_name ()
public void unset ()
Clears the current value in this (if any) and "unsets" the type, this releases all resources associated with this GValue.