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digitalmars.D.learn - what's wrong with my class?

reply Jonathan Villa <jv_vortex msn.com> writes:
...
import std.experimental.allocator : make, dispose;
import std.experimental.allocator.mallocator : Mallocator;

public synchronized class Session
{
     private:
         ASI parent;
         cUser user;
     public:
         static Session create(ASI _parent, 
accounts.user.id_user_t id_user)  nogc
         {
             return Mallocator.instance.make!Session(_parent, 
id_user);
         }

         this (ASI _parent, uint id_user)
         {
             assert(_parent !is null);
             assert(id_user != 0);
             parent = _parent;
             user = Mallocator.instance.make!cUser(id_user, 
parent.stringManager);
         }

         ~this ()
         {
             Mallocator.instance.dispose(user);
         }
}

trying to build it throws "Don't know how to initialize an object 
of type Session with arguments (ASI, uint)
D:\Dmd\dmd2\windows\bin\..\..\src\phobos\std\experimental\allocato
\package.d(455,48):        instantiated from here: emplace!(Session, ASI, uint)
source\alfred\memory.d(51,52):        instantiated from here: 
make!(Session, shared(Mallocator), ASI, uint)
dmd failed with exit code 1."

Can't you see the constructor arguments? xDDDD
What I'm doing wrong? :<
May 04 2016
next sibling parent reply Brian Schott <briancschott gmail.com> writes:
On Wednesday, 4 May 2016 at 23:19:08 UTC, Jonathan Villa wrote:

 What I'm doing wrong? :<


I see that the types of `id_user` aren't necessarily the same 
between `create` and `this`.
May 04 2016
parent reply Jonathan Villa <jv_vortex msn.com> writes:
On Wednesday, 4 May 2016 at 23:33:28 UTC, Brian Schott wrote:

 On Wednesday, 4 May 2016 at 23:19:08 UTC, Jonathan Villa wrote:

 What I'm doing wrong? :<


 I see that the types of `id_user` aren't necessarily the same 
 between `create` and `this`.


Oh, they are indeed same (alias). I wrote uint because I didn't 
want you to confuse with such a large name and I forgot to change 
the other one c:
May 04 2016
parent Brian Schott <briancschott gmail.com> writes:
On Wednesday, 4 May 2016 at 23:34:52 UTC, Jonathan Villa wrote:

 On Wednesday, 4 May 2016 at 23:33:28 UTC, Brian Schott wrote:

 On Wednesday, 4 May 2016 at 23:19:08 UTC, Jonathan Villa wrote:

 What I'm doing wrong? :<


 I see that the types of `id_user` aren't necessarily the same 
 between `create` and `this`.


 Oh, they are indeed same (alias). I wrote uint because I didn't 
 want you to confuse with such a large name and I forgot to 
 change the other one c:


import std.conv:emplace;

synchronized class Session
{
	this(uint u)
	{
		this.u = u;
	}
private:
	uint u;
}

void main(string[] args)
{
	ubyte[128] mem;
	Session s = emplace!Session(mem, 10);
}

Looks like the bug is actually with std.conv.emplace. It works if 
you remove "synchronized".
May 04 2016
prev sibling parent reply Brian Schott <briancschott gmail.com> writes:
On Wednesday, 4 May 2016 at 23:19:08 UTC, Jonathan Villa wrote:

 What I'm doing wrong? :<


All right. D's type system is marking the `Session` constructor 
as `shared`. This makes the check `static if 
(is(typeof(result.__ctor(args))))` in std.conv.emplace fail 
because `result` is a non-shared `Session`. `emplace` is used by 
`make` to actually initialize the memory returned by `malloc`, 
which is why you care about it here. The solution to this is to 
tell `make` that you want it to return a `shared Session`. Once 
you do this the type checks should pass.

tldr: `return Mallocator.instance.make!(shared Session)(_parent, 
id_user);`
May 04 2016
parent Jonathan Villa <jv_vortex msn.com> writes:
On Thursday, 5 May 2016 at 00:03:34 UTC, Brian Schott wrote:

 On Wednesday, 4 May 2016 at 23:19:08 UTC, Jonathan Villa wrote:

 What I'm doing wrong? :<


 All right. D's type system is marking the `Session` constructor 
 as `shared`. This makes the check `static if 
 (is(typeof(result.__ctor(args))))` in std.conv.emplace fail 
 because `result` is a non-shared `Session`. `emplace` is used 
 by `make` to actually initialize the memory returned by 
 `malloc`, which is why you care about it here. The solution to 
 this is to tell `make` that you want it to return a `shared 
 Session`. Once you do this the type checks should pass.

 tldr: `return Mallocator.instance.make!(shared 
 Session)(_parent, id_user);`


You're right! the error doesn't show anymore.
Just one question about 'shared':
That class has an ASI class, should I tag it as 'synchronized' 
too or it won't be necessary? (because is already inside in a 
synchronized class) I suppose I should tag it too as synchronized
May 04 2016