Re: auto & class members

[Robert M. Münch via Digitalmars-d-learn]

On 2018-05-20 17:40:39 +0000, Robert M. Münch said:

Hi Jonathan, great! This got me a step further. So I can declare my 
member now. But I get an implict cast error when I try:

class a {
        ... myStream;
}

class b {
        typeof(a.myStream.filter!(x => x == myMessage)) mySubStream;
}

void myFunc() {
        a myA = new a();
        b myB = new b();

        myB.mySubstream = myA.myStream.filter!(x => x == myMessage);
}

This gives (unnecessary stuff stripped):

Error: cannot implicitly convert expression filter(...) of type 
app.myFunc.filter!(x => x == myMessage) to app.b.filter!(x => x == 
myMessage)

Answering myself: Using an alias helps.

alias typeof(a.myStream.filter!(x => x == myMessage)) myMessageType;

class b {
        myMessageType mySubStream;
}

void myFunc() {
        a myA = new a();
        b myB = new b();

	myB.mySubstream = cast(myMessageType)myA.myStream.filter!(x => x == 
myMessage);
}

But I still don't understand why I can't write things explicitly but 
have to use an alias for this.

--
Robert M. Münch
http://www.saphirion.com
smarter | better | faster