layers: provide a layers-only vector

Signed-off-by: Marcus Fritzsch <marcus_fritzsch@mentor.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/layers.hpp b/src/layers.hpp
index 9dd2036..ec24a74 100644
--- a/src/layers.hpp
+++ b/src/layers.hpp
@@ -30,10 +30,15 @@ struct surface_id_to_layer {
 // to contain its mapping type and the _single_ useful method.
 struct surface_id_to_layer_map {
    typedef std::set<struct surface_id_to_layer> surface_to_layer_map_type;
+   typedef std::vector<unsigned int> layers_type;
 
    surface_to_layer_map_type mapping;
+   layers_type layers;
 
    optional<int> get_layer_for_surface(int surface_id);
+   layers_type::size_type get_layers_count() const {
+      return this->layers.size();
+   }
 };
 
 struct result<struct surface_id_to_layer_map> to_surface_id_to_layer_map(