• Ola Fosheim =?UTF-8?B?R3LDuHN0YWQ=?= (21/21) Nov 27 2019 My understanding is that the current two big goals for D is:
• Dukc (6/11) Nov 27 2019 In the same way as C interfacing works with @safe (or @live). We
• Ola Fosheim =?UTF-8?B?R3LDuHN0YWQ=?= (6/10) Nov 27 2019 There is one difference though, C-frameworks are often designed

Ola Fosheim =?UTF-8?B?R3LDuHN0YWQ=?= <ola.fosheim.grostad gmail.com> writes:

My understanding is that the current two big goals for D is:

1. To have 100% memory safe code as the default.

2. Being able to use large C++ frameworks.


So, these would be two major features, but how are they going to 
interoperate?

Right now ownership/borrowing seems to be discussed entirely in a 
pure D context, but that isn't very helpful if you want to use a 
C++ framework to build an application in D.


So, basically what D needs is a way to annotate C++ interfaces 
with ownership-information so that you can do static analysis on 
safe D code that calls into C++ frameworks and objects.

Static analysis requires knowledge of whether a C++ object is 
reference counted, owning, borrowing and what lifetime guarantees 
the safe D code has to obey by.


Seems to me that working on ownership for D won't help much. You 
need something more abstract that also works for existing C++ 
code.

If not, you end up with 2 languages:

1. An unsafe one for building with C++ frameworks.
2. A safe one for primarily building with D frameworks.

Which seems a bit pointless, considering all the work involved.

Dukc <ajieskola gmail.com> writes:

On Wednesday, 27 November 2019 at 09:20:14 UTC, Ola Fosheim 
Grøstad wrote:
 My understanding is that the current two big goals for D is:

 1. To have 100% memory safe code as the default.

 2. Being able to use large C++ frameworks.


 So, these would be two major features, but how are they going 
 to interoperate?

In the same way as C interfacing works with  safe (or  live). We 
annotate the C function header properly. When that is not enough, 
we make a  trusted wrapper that guards against misuse. Of course 
the impementation of the wrapper is still vurnerable.

Ola Fosheim =?UTF-8?B?R3LDuHN0YWQ=?= <ola.fosheim.grostad gmail.com> writes:

On Wednesday, 27 November 2019 at 15:29:25 UTC, Dukc wrote:
 In the same way as C interfacing works with  safe (or  live). 
 We annotate the C function header properly. When that is not 
 enough, we make a  trusted wrapper that guards against misuse. 
 Of course the impementation of the wrapper is still vurnerable.

There is one difference though, C-frameworks are often designed 
to be used from other languages.

Anyway, probably a good idea to make a list of C++ framworks that 
one has to be able to support and figure out what the 
requirements are.