Re: Calls `this(this)` extra with delegate stuff in the code

[Ali Çehreli via Digitalmars-d-learn]

On 01/21/2017 07:22 PM, Basile B. wrote:
On Sunday, 22 January 2017 at 00:31:38 UTC, Ali Çehreli wrote:
On 01/21/2017 03:36 PM, Ali Çehreli wrote:
> Change the signature and it works without copies:
>
>     this(const(this)) {
>         // ...
>     }

Ugh... :( It's not a post-blit. Then what is it?

Ali

This is a __ctor that takes another instance as param. The param name is
not specified, i.e

struct Foo
{
    this(const(this)){}
}

is the same as

struct Foo
{
    this(const(this) param){}
}

since __PRETTY__FUNCTION__ in the function returns

    "Foo Foo.this(const(Foo) _param_0) ref"

That's strange.
Isn't it mentioned somewhere in the specification that within a function
declaration, "this" resolves to the type of the current aggregate ?

Wow! Thanks.

I know about 'alias this' but this (pun!) is new to me. TIL indeed and 
WAT!!!! (four exclamation marks is right in this case. :o) )

import std.stdio;

struct S {
    void foo(this a = () {
            static assert(is(this));     // 'this' is a type
            return S();
        }()) {

        static assert(is(typeof(this))); // 'this' is an expression
        writeln("foo called for ", this);
    }
                                         // WAT!!!!
}

void main() {
    auto s = S();
    s.foo(s);
}

Ali