Summary

Chapter summary

• Ranges abstract data structures from algorithms and allow them to be used with algorithms seamlessly.

• Ranges are a D concept and are the basis for many features of Phobos.

• Many Phobos algorithms return lazy range objects to accomplish their special tasks.

• UFCS works well with range algorithms.

• When used as InputRange objects, the elements of strings are Unicode characters.

• InputRange requires empty,front, and popFront().

• ForwardRange additionally requires save.

• BidirectionalRange additionally requires back and popBack().

• Infinite RandomAccessRange requires opIndex() over ForwardRange.

• Finite RandomAccessRange requires opIndex() and length over BidirectionalRange.

• std.array.appender returns an OutputRange that appends to slices.

• Slices are ranges of finite RandomAccessRange

• Fixed-length arrays are not ranges.

• The std.range module contains many useful range templates.

• Some of those templates allow templates to be more capable depending on the capabilities of original ranges.

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