To document this intent and prevent misuse, the Go type system provides unidirectional channel types that expose only one or the other of the send and receive operations. The type chan<- int, a send-only channel of int, allows sends but not receives. Conversely, the type <-chan int, a receive-only channel of int, allows receives but not sends. (The position of the <- arrow relative to the chan keyword is a mnemonic.) Violations of this discipline are detected at compile time.
