The D Programming Language's Unofficial Docs
beta
The D Programming Language's Unofficial Docs
beta
Predicate the given ranges are sorted by.
The first range.
The range to subtract from r1.
A range of the difference of r1 and r2.
In the case of multisets, considering that element a appears x times in r1 and y times and r2, the number of occurences of a in the resulting range is going to be x-y if x > y or 0 otherwise.
1 import std.algorithm.comparison : equal; 2 import std.range.primitives : isForwardRange; 3 4 //sets 5 int[] a = [ 1, 2, 4, 5, 7, 9 ]; 6 int[] b = [ 0, 1, 2, 4, 7, 8 ]; 7 assert(equal(setDifference(a, b), [5, 9])); 8 static assert(isForwardRange!(typeof(setDifference(a, b)))); 9 10 // multisets 11 int[] x = [1, 1, 1, 2, 3]; 12 int[] y = [1, 1, 2, 4, 5]; 13 auto r = setDifference(x, y); 14 assert(equal(r, [1, 3])); 15 assert(setDifference(r, x).empty);
Lazily computes the difference of r1 and r2. The two ranges are assumed to be sorted by less. The element types of the two ranges must have a common type.