A list-update policy that unconditionally moves elements to the front of the list.
| Parameter | Description | Default Value | 
| Metadata_Reference | Metadata reference type. | std::allocator< move_to_front_update_metadata>:: reference | 
| Method | Description | 
| void swap (move_to_front_update_policy &r_other) | Swaps content. | 
| Type | Definition | Description | 
| metadata_type | move_to_front_update_metadata | Metadata on which this functor operates. | 
| metadata_reference | Metadata_Reference | Reference to metadata on which this functor operates. | 
| Method | Description | 
| metadata_type operator() () const | Creates a metadata object. | 
| bool operator() (metadata_reference r_data) const | Decides whether a metadata object should be moved to the front of the list. |