Like gtk.builder.Builder.valueFromString, this function demarshals
a value from a string, but takes a #GType instead of #GParamSpec.
This function calls gobject.value.Value.init_ on the value argument, so it
need not be initialised beforehand.
Upon errors false will be returned and error will be assigned a
#GError from the #GTK_BUILDER_ERROR domain.
Like gtk.builder.Builder.valueFromString, this function demarshals a value from a string, but takes a #GType instead of #GParamSpec. This function calls gobject.value.Value.init_ on the value argument, so it need not be initialised beforehand.
Upon errors false will be returned and error will be assigned a #GError from the #GTK_BUILDER_ERROR domain.