• chmike (6/6) May 26 2016 I couldn't find any information about this on the dlang web site.
• ArturG (5/12) May 26 2016 auto mc = new MyClass;
• Jonathan M Davis via Digitalmars-d-learn (17/23) May 26 2016 If you put any attribute on a class that's not specifically for a class
• Basile B. (30/37) May 26 2016 Since immutable is transitive everything in your class will be.

chmike <christophe meessen.net> writes:

I couldn't find any information about this on the dlang web site.

What is the effect adding the immutable attribute to a class like 
this

immutable class MyClass { ... }

The compiler doesn't complain.
Will it add the immutable attribute to all members ?

ArturG <var.spool.mail700 gmail.com> writes:

On Thursday, 26 May 2016 at 14:12:23 UTC, chmike wrote:
 I couldn't find any information about this on the dlang web 
 site.

 What is the effect adding the immutable attribute to a class 
 like this

 immutable class MyClass { ... }

 The compiler doesn't complain.
 Will it add the immutable attribute to all members ?

auto mc = new MyClass;

typeof(mc.someFieldOrFun).stringof.writeln; says yes

and if you define opCall you need to use
auto mc = new immutable MyClass;

Jonathan M Davis via Digitalmars-d-learn writes:

On Thursday, May 26, 2016 14:12:23 chmike via Digitalmars-d-learn wrote:
 I couldn't find any information about this on the dlang web site.

 What is the effect adding the immutable attribute to a class like
 this

 immutable class MyClass { ... }

 The compiler doesn't complain.
 Will it add the immutable attribute to all members ?

If you put any attribute on a class that's not specifically for a class
(like abstract or final), then it will mark all of its members with that
attribute, which is almost never what you want. It's equivalent to doing
something like

immutable
{
    class MyClass
    {
    }
}

or

class MyClass
{
immutable:
}

- Jonathan M Davis

Basile B. <b2.temp gmx.com> writes:

On Thursday, 26 May 2016 at 14:12:23 UTC, chmike wrote:
 I couldn't find any information about this on the dlang web 
 site.

 What is the effect adding the immutable attribute to a class 
 like this

 immutable class MyClass { ... }

 The compiler doesn't complain.
 Will it add the immutable attribute to all members ?

Since immutable is transitive everything in your class will be. 
So basically the only thing you can do is

- create a new immutable(MyClass)
- sets the instances variables in the ctor.
- calls the method (which can't do anything on the variables).

And that's all, e.g:

----
immutable class Foo
{
     int i;
     this(int i){this.i = i;}
     void method(){}
}

void main()
{
     immutable(Foo) foo = new immutable(Foo)(1);
     //foo.i = 8; // not possible since i is immutable
     Foo foo1 = cast(Foo) foo; // cast away immutable from the 
type.
     //foo1.method; // not pissible since method is immutable
}
----

So it's more or less useless, unless you want to wrap some 
variables in a class to simplify completion in the IDE or 
whatever other reasons.

_________________

By the way the doc for "immutable class Stuff" is here: 
https://dlang.org/spec/const3.html#immutable_type, it's a type 
constructor. "immutable" is fully part of the type.