I've tagged the ref-returning functions (in this case `opSlice`) with `return scope` for my statically allocated array struct at

https://github.com/nordlow/phobos-next/blob/master/src/arrayn.d

but for some reason the scope-checking (via -dip1000) allows both

https://github.com/nordlow/phobos-next/blob/bde41f92b5373dd1365ad19ef9d0ecee4eb2d2cd/src/arrayn.d#L350

and

https://github.com/nordlow/phobos-next/blob/bde41f92b5373dd1365ad19ef9d0ecee4eb2d2cd/src/arrayn.d#L390

to compile eventhough the life-time of the slices clearly outlives (is defined prior to) the lifetime of the fixed-length (stack-allocated) array/string struct instance.

Have I missed something or is this simply not yet supported?

On Tuesday, 9 May 2017 at 11:52:35 UTC, Nordlöw wrote:
> I've tagged the ref-returning functions (in this case `opSlice`) with `return scope` for my statically allocated array struct at

Here's a simpler example

https://github.com/nordlow/phobos-next/blob/cf85f449d24981fbe6269f8096db23282e2fbb65/tests/test_scope.d

On Tuesday, 9 May 2017 at 12:25:29 UTC, Nordlöw wrote:
> On Tuesday, 9 May 2017 at 11:52:35 UTC, Nordlöw wrote:
>> I've tagged the ref-returning functions (in this case `opSlice`) with `return scope` for my statically allocated array struct at
>
> Here's a simpler example
>
> https://github.com/nordlow/phobos-next/blob/cf85f449d24981fbe6269f8096db23282e2fbb65/tests/test_scope.d

Looks like a bug, if you change "auto" to "int[]" it starts complaining in f(). I have a question though, why is the syntax like this:

> auto opSlice() return scope;

?

I don't see such in the DIP, proposed there is simply "scope" to the left of the declaration, i.e.

> scope auto opSlice();

Although with that syntax dmd complains about escaping 'this', as if it was scope { auto opSlice(); }.

Is 'return scope' the syntax that is supposed to be used and it's just not reflected in the DIP, or?..

On Tuesday, 9 May 2017 at 12:25:29 UTC, Nordlöw wrote:
> On Tuesday, 9 May 2017 at 11:52:35 UTC, Nordlöw wrote:
>> I've tagged the ref-returning functions (in this case `opSlice`) with `return scope` for my statically allocated array struct at
>
> Here's a simpler example
>
> https://github.com/nordlow/phobos-next/blob/cf85f449d24981fbe6269f8096db23282e2fbb65/tests/test_scope.d

If I change the return value of `S.opSlice` to `int[]` correct `scope`-error handling kicks in.

Tha is, scope checking via -dip1000 works for

struct S
{
    @safe pure nothrow @nogc
    int[] opSlice() return scope
    {
        return x[];
    }
    int[4] x;
}

but not for

struct S
{
    @safe pure nothrow @nogc
    auto opSlice() return scope
    {
        return x[];
    }
    int[4] x;
}

.

I'll write a Bugzilla issue later today.

On Tuesday, 9 May 2017 at 13:30:49 UTC, Nordlöw wrote:
> I'll write a Bugzilla issue later today.

https://issues.dlang.org/show_bug.cgi?id=17388