Inconsistent overload resolution depending on member values of Rvalue struct objects

[dlangBugzillaToGithub]

Ali Cehreli (@acehreli) reported this on 2017-01-01T01:33:24Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=17050

Description

Because no member nor struct type is different below, all calls are expected to be resolved to the same foo overload. However, that's not the case:

struct S {
    const(int)[] c;
}

int foo(S s) {
    return 1;
}

int foo(immutable(S) s) {
    return 2;
}

void main() {

    // This call is resolved to foo(S):
    const(int)[] arr;
    assert(foo(const(S)(arr)) == 1);

    // These are unexpectedly resolved to foo(immutable(S)):
    assert(foo(const(S)()) == 1);        // FAILS
    assert(foo(const(S)(null)) == 1);    // FAILS
}

Ali

[dlangBugzillaToGithub]

acehreli commented on 2017-01-01T01:35:42Z

Related forum thread:

  http://forum.dlang.org/post/o4447c$21lf$1@digitalmars.com

Ali