Ceremony of the Keys (London) through the Bloody Tower archway. The Chief Warder and the escort were blown off their feet, but they recovered and carried on. The Tower holds a letter from the Officer of the Guard apologising to King George VI that the ceremony was late, along with a reply from the King which says that the officer is not to be punished as the delay was due to enemy action. Between 40 and 50 visitors are allowed access to the ceremony each night, under escort. Tickets are free but must be obtained in advance from Historic Royal Palaces, the organisation that looks
Locks-and-keys Locks-and-keys Locks-and-keys is a solution to dangling pointers in computer programming languages. The locks-and-keys approach represents pointers as ordered pairs (key, address) where the key is an integer value. Heap-dynamic variables are represented as the storage for the variable plus a cell for an integer lock value. When a variable is allocated, a "lock value" is created and placed both into the variable's cell and into the pointer's key cell. Every access to the pointer compares these two values, and access is allowed only if the values match. When a variable is deallocated, the key of its pointer is modified