[Issue 13119] `struct` constructor attributes inferred like field destructor is called on initialization

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=13119

Stanislav Blinov <stanislav.blinov at gmail.com> changed:

           What    |Removed                     |Added
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                 CC|                            |stanislav.blinov at gmail.com

--- Comment #1 from Stanislav Blinov <stanislav.blinov at gmail.com> ---
Error in the original report is trivially worked around by replacing `s = S(0)`
with `s = 0` as that is supported by S's constructor.

However, the error comes back as soon as more than one argument gets involved:

struct S
{
    this(int, int) @safe pure nothrow @nogc { }
    ~this() { }
}

struct T
{
    S s;

    this(int) @safe pure nothrow @nogc
    {
        s = S(0, 1); // attribute errors here as this is introducing a dtor
call
    }
}

Two workarounds:

alias AliasSeq(T...) = T;
s = AliasSeq!(0, 1); // works for literals, not for moving stuff

import core.lifetime : forward;
s = forward!args;    // works for moving and copying, but not for literals

Observation about `nothrow` not being looked at is still valid.

Initialization shouldn't require a destructor call, as right hand side should
ostensibly be constructed at &s, should it not?

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