RandomAccessRange: Finite

The following are all of the requirements of a RandomAccessRange that is based on a finite BidirectionalRange:

• empty,front and popFront() required by InputRange

• save required by ForwardRange

• back and popBack() required by BidirectionalRange

• opIndex() required by RandomAccessRange

• length which provides the length of the range

Example

As an example of a finite RandomAccessRange, let’s define a range that works similar to std.range.chain. The chain() function presents the elements of a number of separate ranges as if they are elements of a single larger range. Although chain() works with any type of element and any type of range, to keep the example short, let’s implement a range that works only with int slices.

Let’s name this range Together and expect the following behavior from it:

auto range = Together([ 1, 2, 3 ], [ 101, 102, 103]); 
writeln(range[4]);

When constructed with the two ...