ddash.algorithm.equal

1 // single elements
2 assert(!equal(2, 4));
3 
4 // unary predicate function applied to elements then compared
5 assert( equal!(a => a % 2 == 0)(2, 4));
6 assert( equal!q{a % 2 == 0}(2, 4));
7 
8 // binary predicate used to compare elements
9 assert(!equal!((a, b) => a == b)(2, 4));
10 assert( equal!q{a != b}(2, 4));
11 
12 // compare ranges of ranges of different range types but same value types
13 import std.algorithm: map, filter;
14 auto r1 = [1, 2, 3].map!"a";
15 auto r2 = [1, 2, 3].filter!"true";
16 assert( equal([r1], [r2]));
17 
18 assert( equal([1, 2, 3], [1, 2, 3]));
19 assert( equal([[1], [2], [3]], [[1], [2], [3]]));
20 
21 static assert(!__traits(compiles, equal!(a => a)(1, "hi")));

1 struct S {
2     int x;
3     int y;
4 }
5 
6 auto s1 = S(1, 2);
7 auto s2 = S(2, 2);
8 
9 assert( equalBy!"y"(s1, s2));
10 assert(!equalBy!"x"(s1, s2));
11 
12 auto r1 = [s2, s2];
13 auto r2 = [s1, s1];
14 
15 assert( equalBy!"y"(r1, r2));
16 assert(!equalBy!"x"(r1, r2));