[REG2.072] "cannot append type const(T) to type T[]" in .dup

[dlangBugzillaToGithub]

Vladimir Panteleev (@CyberShadow) reported this on 2018-03-13T15:56:49Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=18606

CC List

• Walter Bright (@WalterBright)
• John Colvin

Description

///////// test.d /////////
struct S
{
    struct T
    {
        int foo;
        int[] bar;
    }

    struct M()
    {
        T[] arr;

        this(this)
        {
            arr = arr.dup;
        }
    }

    M!() m;
}
//////////////////////////

Introduced in https://github.com/dlang/dmd/pull/5500

[dlangBugzillaToGithub]

bugzilla (@WalterBright) commented on 2018-05-14T13:39:43Z

(In reply to Vladimir Panteleev from comment #0)
> Introduced in https://github.com/dlang/dmd/pull/5500

This is why I don't like 700 line PRs spread across 18 files :-(

[dlangBugzillaToGithub]

dlang-bugzilla (@CyberShadow) commented on 2018-05-14T19:39:02Z

The commits are big too, but if it helped, I can bisect it down to the commit.

[dlangBugzillaToGithub]

john.loughran.colvin commented on 2019-01-11T18:12:39Z

Related:

struct S
{
    string get(string key)
    {
        return key;
    }
    alias get this;
}

void main()
{
    S[] a;
    auto b = a.dup;
}

/dlang/dmd/linux/bin64/../../src/druntime/import/object.d(4473): Error: mutable method onlineapp.S.get is not callable using a const object
/dlang/dmd/linux/bin64/../../src/druntime/import/object.d(4473):        Consider adding const or inout to onlineapp.S.get
/dlang/dmd/linux/bin64/../../src/druntime/import/object.d(4460): Error: template instance `object._dup!(const(S), S)` error instantiating
/dlang/dmd/linux/bin64/../../src/druntime/import/object.d(4424):        instantiated from here: _trustedDup!(const(S), S)
onlineapp.d(13):        instantiated from here: dup!(S)


and


struct S
{
    string get(string key) const
    {
        return key;
    }
    alias get this;
}

void main()
{
    S[] a;
    auto b = a.dup;
}

/dlang/dmd/linux/bin64/../../src/druntime/import/object.d(4473): Error: function onlineapp.S.get(string key) const is not callable using argument types () const
/dlang/dmd/linux/bin64/../../src/druntime/import/object.d(4473):        missing argument for parameter #1: string key
/dlang/dmd/linux/bin64/../../src/druntime/import/object.d(4460): Error: template instance `object._dup!(const(S), S)` error instantiating
/dlang/dmd/linux/bin64/../../src/druntime/import/object.d(4424):        instantiated from here: _trustedDup!(const(S), S)
onlineapp.d(13):        instantiated from here: dup!(S)