A slot is a small opening. It is a rectangular area, usually found in the middle of the ice or in an offensive zone, where players may shoot shots. In hockey, a high slot is the place right in front of the goaltender. Another location is a low slot, located between face-off circles.
Slot machines are a popular form of gambling. They accept cash and allow anyone to play. Unlike most other forms of gambling, slot machines require little skill. The reels spin with a pull of the lever and a payout is awarded based on the number of symbols lined up on the pay line.
Modern slot machines use computers instead of gears. In addition to more sophisticated money-handling systems, they also have flashier light and sound displays. These machines also have bonus rounds that include interactive elements. Typical themes of slot games include fruits, bells, and stylized lucky sevens.
When called directly, slots follow normal C++ rules. However, if a slot is invoked by a component that is not related to the slot, the slot will report a runtime error. This means that a slot can be used to receive signals, but it does not know if the signals are connected to it.
If you are calling a signal through a slot, you should only use a class that defines the signal. Otherwise, you might end up executing the private slot in an unrelated class.
A slot can be connected to a signal by using the QObject::connect() method. Using the connect() function to emit a signal to a slot will require an overhead of about ten times slower than calling the receiver directly.