Newbie comments about D

[Jarrett Billingsley]

"Kristian" <kjkilpi at gmail.com> wrote in message 
news:op.tefyzndb5xlco7 at mist...

(sorry, my newsreader is, for some reason, not quoting your message [and 
your message alone] properly..)

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--- 5 ---

Hmm, could it be possible to automatically add auto/local attribute to
objects that are not returned (by a function) and that are not assigned to
anything? For example:

class File {...}  //the file is closed in the destructor

void f() {
     File f = new File;  //auto File f = new File;

     f.open("myfile.txt");
     f.doSomething();
}

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What if you did something like this:

void f()
{
    File f = new File("foo.txt");
    aFunctionThatStoresTheFileHandleElsewhere(f);
}

With the current semantics of RAII class references, this is perfectly 
legal, and would cause a terrible bug whereby 'f' would be destroyed at the 
end of the function and would no longer be a valid reference "elsewhere."

It's certainly a very interesting optimization idea, but it would require 
the compiler to know more than it possibly can, or it would require placing 
very stringent restrictions on how RAII (or these "implicit RAII") class 
references could be used.