A range of the symmetric difference between r1 and r2.
import std.algorithm.comparison : equal; import std.range.primitives : isForwardRange; // sets int[] a = [ 1, 2, 4, 5, 7, 9 ]; int[] b = [ 0, 1, 2, 4, 7, 8 ]; assert(equal(setSymmetricDifference(a, b), [0, 5, 8, 9][])); static assert(isForwardRange!(typeof(setSymmetricDifference(a, b)))); //mutisets int[] c = [1, 1, 1, 1, 2, 2, 2, 4, 5, 6]; int[] d = [1, 1, 2, 2, 2, 2, 4, 7, 9]; assert(equal(setSymmetricDifference(c, d), setSymmetricDifference(d, c))); assert(equal(setSymmetricDifference(c, d), [1, 1, 2, 5, 6, 7, 9]));
Lazily computes the symmetric difference of r1 and r2, i.e. the elements that are present in exactly one of r1 and r2. The two ranges are assumed to be sorted by less, and the output is also sorted by less. The element types of the two ranges must have a common type.
If both ranges are sets (without duplicated elements), the resulting range is going to be a set. If at least one of the ranges is a multiset, the number of occurences of an element x in the resulting range is abs(a-b) where a is the number of occurences of x in r1, b is the number of occurences of x in r2, and abs is the absolute value.
If both arguments are ranges of L-values of the same type then SetSymmetricDifference will also be a range of L-values of that type.