docs: Move GValue documentation to Markdown

Helps: #3037

gobject/gvalue.c

@@ -31,122 +31,6 @@
 #include "gtype-private.h"
 
 
-/**
- * SECTION:generic_values
- * @short_description: A polymorphic type that can hold values of any
- *     other type
- * @see_also: 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][gobject-Standard-Parameter-and-Value-Types]
- *     for details
- * @title: Generic values
- *
- * 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 an 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. Before 
- * destruction you must always use g_value_unset() to make sure allocated
- * memory is freed.
- *
- * 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 code in the example program below demonstrates #GValue's
- * features.
- *
- * |[<!-- language="C" --> 
- * #include <glib-object.h>
- *
- * static void
- * int2string (const GValue *src_value,
- *             GValue       *dest_value)
- * {
- *   if (g_value_get_int (src_value) == 42)
- *     g_value_set_static_string (dest_value, "An important number");
- *   else
- *     g_value_set_static_string (dest_value, "What's that?");
- * }
- *
- * int
- * main (int   argc,
- *       char *argv[])
- * {
- *   // GValues must be initialized
- *   GValue a = G_VALUE_INIT;
- *   GValue b = G_VALUE_INIT;
- *   const gchar *message;
- *
- *   // The GValue starts empty
- *   g_assert (!G_VALUE_HOLDS_STRING (&a));
- *
- *   // Put a string in it
- *   g_value_init (&a, G_TYPE_STRING);
- *   g_assert (G_VALUE_HOLDS_STRING (&a));
- *   g_value_set_static_string (&a, "Hello, world!");
- *   g_printf ("%s\n", g_value_get_string (&a));
- *
- *   // Reset it to its pristine state
- *   g_value_unset (&a);
- *
- *   // It can then be reused for another type
- *   g_value_init (&a, G_TYPE_INT);
- *   g_value_set_int (&a, 42);
- *
- *   // Attempt to transform it into a GValue of type STRING
- *   g_value_init (&b, G_TYPE_STRING);
- *
- *   // An INT is transformable to a STRING
- *   g_assert (g_value_type_transformable (G_TYPE_INT, G_TYPE_STRING));
- *
- *   g_value_transform (&a, &b);
- *   g_printf ("%s\n", g_value_get_string (&b));
- *
- *   // Attempt to transform it again using a custom transform function
- *   g_value_register_transform_func (G_TYPE_INT, G_TYPE_STRING, int2string);
- *   g_value_transform (&a, &b);
- *   g_printf ("%s\n", g_value_get_string (&b));
- *   return 0;
- * }
- * ]|
- *
- * See also [gobject-Standard-Parameter-and-Value-Types] for more information on
- * validation of #GValue.
- *
- * For letting a #GValue own (and memory manage) arbitrary types or pointers,
- * they need to become a [boxed type][gboxed]. The example below shows how
- * the pointer `mystruct` of type `MyStruct` is used as a [boxed type][gboxed].
- *
- * |[<!-- language="C" -->
- * typedef struct { ... } MyStruct;
- * G_DEFINE_BOXED_TYPE (MyStruct, my_struct, my_struct_copy, my_struct_free)
- *
- * // These two lines normally go in a public header. By GObject convention,
- * // the naming scheme is NAMESPACE_TYPE_NAME:
- * #define MY_TYPE_STRUCT (my_struct_get_type ())
- * GType my_struct_get_type (void);
- *
- * void
- * foo ()
- * {
- *   GValue *value = g_new0 (GValue, 1);
- *   g_value_init (value, MY_TYPE_STRUCT);
- *   g_value_set_boxed (value, mystruct);
- *   // [... your code ....]
- *   g_value_unset (value);
- *   g_free (value);
- * }
- * ]|
- */
-
-
 /* --- typedefs & structures --- */
 typedef struct {
   GType src_type;