https://issues.dlang.org/show_bug.cgi?id=13732

Nick Treleaven <nick@geany.org> changed:

           What    |Removed                     |Added
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                 CC|                            |nick@geany.org

--- Comment #1 from Nick Treleaven <nick@geany.org> ---
What's the advantage over a normal template type parameter?

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https://issues.dlang.org/show_bug.cgi?id=13732

--- Comment #2 from Meta <monkeyworks12@hotmail.com> ---
import std.stdio;

class Base {
    void test1(T = typeof(this))() {
        writeln("test1: ", T.stringof);
    }

    void test2(this T)() {
        writeln("test2: ", T.stringof);
    }
}

class Derived: Base {
}

void main()
{
    new Base().test1();    //test1: Base
    new Base().test2();    //test2: Base

    new Derived().test1(); //test1: Base
    new Derived().test2(); //test1: Derived
}

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https://issues.dlang.org/show_bug.cgi?id=13732

--- Comment #3 from Nick Treleaven <nick@geany.org> ---
Isn't comment 2 what we have already? The title says 'allow any type to be passed' and the example uses int.

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https://issues.dlang.org/show_bug.cgi?id=13732

--- Comment #4 from Meta <monkeyworks12@hotmail.com> ---
> Isn't comment 2 what we have already?

Ya, I created this issue because any template allows you to use the `this T` syntax, and it will accept any type (which seemed like a bug at the time). I still think it's confusing, and it does nothing in a template that's not nested in an aggregate, but might not necessarily be behaviour that needs to be fixed.

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https://issues.dlang.org/show_bug.cgi?id=13732

--- Comment #5 from Nick Treleaven <nick@geany.org> ---
Oh I see, it should only be allowed for methods.

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https://issues.dlang.org/show_bug.cgi?id=13732

Dlang Bot <dlang-bot@dlang.rocks> changed:

           What    |Removed                     |Added
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           Keywords|                            |pull

--- Comment #6 from Dlang Bot <dlang-bot@dlang.rocks> ---
@ntrel created dlang/dmd pull request #14434 "Fix Issue 13732 - non-member templates can use "template this"" fixing this issue:

- Fix Issue 13732 - non-member templates can use "template this"

https://github.com/dlang/dmd/pull/14434

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https://issues.dlang.org/show_bug.cgi?id=13732

--- Comment #7 from Dlang Bot <dlang-bot@dlang.rocks> ---
@ntrel created dlang/dmd pull request #14447 "Fix Issue 13732 - non-member templates can use "template this"" fixing this issue:

- Fix Issue 13732 - non-member templates can use "template this"

  Error if a TemplateThisParameter is declared where `typeof(this)` would
  be an error.
  Error if a TemplateThisParameter is passed a type that doesn't convert
  to `const typeof(this)`.

  Note: This is done with a dummy specialization, which causes the correct
  semantic error messages even for mixin and may be more efficient than
  checking this in dtemplate.d.

https://github.com/dlang/dmd/pull/14447

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https://issues.dlang.org/show_bug.cgi?id=13732

Dlang Bot <dlang-bot@dlang.rocks> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #8 from Dlang Bot <dlang-bot@dlang.rocks> ---
dlang/dmd pull request #14434 "Fix Issue 13732 - non-member templates can use "template this"" was merged into master:

- c22f40bb47b98a0a18ffca0a6766047e81784d35 by Nick Treleaven:
  Fix Issue 13732 - non-member templates can use "template this"

https://github.com/dlang/dmd/pull/14434

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