• denizzzka (7/7) Oct 15 2012 void main()
• thedeemon (3/6) Oct 15 2012 Because shared(S) and S are different types. Either declare s as
• denizzzka (3/9) Oct 15 2012 Why it was made in the language? This can be a safe automatic
• thedeemon (12/16) Oct 15 2012 Theoretically compiler can work with shared and non-shared types
• denizzzka (1/1) Oct 15 2012 Thanks!

"denizzzka" <4denizzz gmail.com> writes:

void main()
{
     struct S { int payload; }

     S* s = new shared (S); // Why this is a illegal?
}


Error: cannot implicitly convert expression (new shared(S)) of 
type shared(S)* to S*

"thedeemon" <dlang thedeemon.com> writes:

On Monday, 15 October 2012 at 15:15:57 UTC, denizzzka wrote:
     S* s = new shared (S); // Why this is a illegal?
 Error: cannot implicitly convert expression (new shared(S)) of 
 type shared(S)* to S*

Because shared(S) and S are different types. Either declare s as 
shared too or use a cast.

"denizzzka" <4denizzz gmail.com> writes:

On Monday, 15 October 2012 at 15:27:03 UTC, thedeemon wrote:
 On Monday, 15 October 2012 at 15:15:57 UTC, denizzzka wrote:
    S* s = new shared (S); // Why this is a illegal?
 Error: cannot implicitly convert expression (new shared(S)) of 
 type shared(S)* to S*

 Because shared(S) and S are different types. Either declare s 
 as shared too or use a cast.

Why it was made in the language? This can be a safe automatic 
conversion I think.

"thedeemon" <dlang thedeemon.com> writes:

On Monday, 15 October 2012 at 15:34:43 UTC, denizzzka wrote:

 Because shared(S) and S are different types. Either declare s 
 as shared too or use a cast.

 Why it was made in the language? This can be a safe automatic 
 conversion I think.

Theoretically compiler can work with shared and non-shared types 
very differently,  with the latter it can do all the work in 
registers without always updating the memory because it knows no 
other threads will look at this data. Shared data is much more 
volatile. So actually not only automatic but also explicit cast 
should be illegal. I don't know how much differently the compiler 
deals with these types right now though.

Currently the whole story of separating shared and local types is 
not fully thought, imho, we need some kind of 
shared-polymorphism, without it we have to use casts quite often 
and it's not a right thing to do.

"denizzzka" <4denizzz gmail.com> writes:

Thanks!