A narrow opening, hole, groove, or slit, typically one for receiving something such as coins or paper. He dropped a coin in the slot and dialled. Also used: (Australian Rules football, rugby) A space between the face-off circles on an ice hockey rink. (informal) A time or place for doing something; a vacancy: She slotted the new filter into the machine.
In a slot machine, a lever or button (physical or virtual) is activated by a computer to spin the reels and stop them at random positions. When the symbols match a paytable, the player earns credits based on the number of matching symbols and the paytable’s value. The symbols vary by game, but classic symbols include fruit, bells, and stylized lucky sevens. Modern slot machines have a variety of themes, and the symbols are aligned with the theme.
In C++, slots have the same rules as regular member functions and may be invoked by any class. However, the overhead associated with slots is far less than that of conventional function calls. In addition, slots are a convenient way to pass arguments between classes and objects.