Using `alias this` it's easy to make wrapper for structure that calls wrapped structure methods like its own. This is one way - from wrapper to wrapped transformation. Is it possible to create the opposite way from wrapped to wrapper?

https://run.dlang.io/is/Avyu3I

All calls to Bar is redirected to Foo, but output of Foo is not redirected to Bar.

On Wednesday, 11 October 2017 at 12:35:51 UTC, drug wrote:
> Using `alias this` it's easy to make wrapper for structure that calls wrapped structure methods like its own. This is one way - from wrapper to wrapped transformation. Is it possible to create the opposite way from wrapped to wrapper?
>
> https://run.dlang.io/is/Avyu3I
>
> All calls to Bar is redirected to Foo, but output of Foo is not redirected to Bar.

I don't see how compiler can just deduce that... In either case you can just wrap the expression with another Bar():

auto v5 = Bar(Bar(Foo(2)) + Bar(Foo(3)));

On Wednesday, 11 October 2017 at 12:35:51 UTC, drug wrote:
> Using `alias this` it's easy to make wrapper for structure that calls wrapped structure methods like its own. This is one way - from wrapper to wrapped transformation. Is it possible to create the opposite way from wrapped to wrapper?
>
> https://run.dlang.io/is/Avyu3I
>
> All calls to Bar is redirected to Foo, but output of Foo is not redirected to Bar.

How about a template for the opBinary operator?
https://run.dlang.io/is/7gi5Wl

The code relies on the fact, that only one alias this is allowed.
https://dlang.org/spec/class.html#AliasThis

If more are possible at some moment, I suppose it will be possible to static foreach over them to choose the right member, based on its type.

On Saturday, 14 October 2017 at 11:25:20 UTC, Alex wrote:
of course, with the proper operator in line 32

return T(mixin("this" ~ op ~ "f"));

https://run.dlang.io/is/jGKVYN

On Saturday, 14 October 2017 at 12:39:17 UTC, Alex wrote:

ok, the last version for now. Without assumptions on alias number. Sorry for noise.

https://run.dlang.io/is/OSJYtY

14.10.2017 16:23, Alex пишет:
> On Saturday, 14 October 2017 at 12:39:17 UTC, Alex wrote:
> 
> ok, the last version for now. Without assumptions on alias number. Sorry for noise.
> 
> https://run.dlang.io/is/OSJYtY
That's cool, but unfortunately demands access to source code of Foo, it's not my case(
I improved your example a little bit - https://run.dlang.io/is/yeKofN, it's really great. Need polish of course, but this is a way to get more inheritance with structures.