[glib] gvariant.c: Elaborate on GVariant concept and its use

[Matthias Clasen <matthiasc src gnome org>]

commit 985ae37d198bef5bf386416a46f944d9952940be
Author: Bastian Ilsø <bastianilso gnome org>
Date:   Sat May 2 19:51:46 2015 +0200

    gvariant.c: Elaborate on GVariant concept and its use
    
    Inserts a paragraph in the start of the description
    explaining briefly the concept of GVariant as a
    variant datatypes using examples and explaining
    a few use cases where GVariant can be useful.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=748806

 glib/gvariant.c |   20 ++++++++++++++++----
 1 files changed, 16 insertions(+), 4 deletions(-)
---
diff --git a/glib/gvariant.c b/glib/gvariant.c
index 85bb1ca..d282491 100644
--- a/glib/gvariant.c
+++ b/glib/gvariant.c
@@ -40,10 +40,22 @@
  * @short_description: strongly typed value datatype
  * @see_also: GVariantType
  *
- * #GVariant is a variant datatype; it stores a value along with
- * information about the type of that value.  The range of possible
- * values is determined by the type.  The type system used by #GVariant
- * is #GVariantType.
+ * #GVariant is a variant datatype; it can contain one or more values
+ * along with information about the type of the values.
+ * A GVariant can for example contain an array of two strings, an integer or a dictionary.
+ * This is useful for example when sending data via D-Bus, or when
+ * interacting with GSettings or GActions.
+ * When declaring a new GVariant, you parse the data you want to store in it
+ * along with a string representing the type of data you wish to parse to it.
+ * If you, for example, want to make a GVariant holding a string:
+ * |[<!-- language="C" -->
+ * g_variant_new('u','40');
+ * ]|
+ * The string 'u' tells GVariant that the data parsed to it (40) is an integer.
+ * More advanced examples of #GVariant in use can be found in documentation for
+ * [GVariant format strings][gvariant-format-strings-pointers].
+ * The range of possible values is determined by the type.
+ * The type system used by #GVariant is #GVariantType. 
  *
  * #GVariant instances always have a type and a value (which are given
  * at construction time).  The type and value of a #GVariant instance