Typeinfo.compare uses bitwise comparison for structs

[dlangBugzillaToGithub]

hsteoh reported this on 2013-07-09T13:48:31Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=10588

Description

CODE:

------snip------
struct S {
        int[] data;
}
void main() {
        auto s = S([1,2,3]);
        auto t = S([1,2,3]);
        auto u = S([1,2,4]);

        assert(s == t);
        assert(s != u);
        assert(typeid(s).compare(&s, &t) == 0); // FAILS
        assert(typeid(s).compare(&s, &u) != 0);
}
------snip------

Since S doesn't define opEquals or opCmp, the typeinfo's .compare is just the default provided by DMD. However, it uses bitwise comparison, whereas == uses field-wise comparison.

[dlangBugzillaToGithub]

hsteoh commented on 2014-12-05T22:53:49Z

Still happens on git HEAD as of today. Tested on Linux/64.

[dlangBugzillaToGithub]

hsteoh commented on 2019-12-10T18:52:37Z

Still happens as of git master (5a3783db46b1b16b76c3afa493b17130b76b1eda).