cycle

fnauto cycle(R)(R input) if (isInputRange!R)

Ditto

fnCycle!R cycle(R)(R input, size_t index = 0) if (isRandomAccessRange!R && !isInfinite!R)

Ditto

fnCycle!R cycle(R)(ref R input, size_t index = 0) if (isStaticArray!R) @system

Ditto