Evaluates the watched expression and on success stores the result
in value.
This is equivalent to calling [methodGtk.Expression.evaluate] with the
expression and this pointer originally used to create watch.
an empty GValue to be set
Acquires a reference on the given GtkExpressionWatch.
Releases a reference on the given GtkExpressionWatch.
If the reference was the last, the resources associated to self are
freed.
Stops watching an expression.
See [methodGtk.Expression.watch] for how the watch
was established.
An opaque structure representing a watched
GtkExpression.The contents of
GtkExpressionWatchshould only be accessed through the provided API.