• Era Scarecrow (13/45) May 04 2012 This is a topic pulled from D.learn.
• Era Scarecrow (15/25) May 07 2012 Thinking about this, perhaps it should attempt the following

"Era Scarecrow" <rtcvb32 yahoo.com> writes:

On Saturday, 5 May 2012 at 04:15:21 UTC, Jonathan M Davis wrote:
 On Saturday, May 05, 2012 05:50:26 Era Scarecrow wrote:
 On Saturday, 5 May 2012 at 03:32:06 UTC, Jonathan M Davis 
 wrote:
 ---------
 Func­tions are over­loaded based on how well the 
 ar­gu­ments to a func­tion can match up with the 
 pa­ra­me­ters. The func­tion with the  best match is 
 se­lected. The lev­els of match­ing are:
 
 1. no match
 2. match with im­plicit con­ver­sions
 3. match with con­ver­sion to const
 4. exact match
 ---------


 
 Hmm maybe it should have a preference for Lvalue vs Rvalue... 
 So... Walter or Andrei?
 
   1. no match
   2. match with im­plicit con­ver­sions (Lvalue required)
   3. match with con­ver­sion to const (Lvalue required)
   4. match with im­plicit con­ver­sions
   5. match with con­ver­sion to const
   6. exact match

 This will likely be _very_ relevant to the proposed changes  
 which make ref and const ref work with rvalues (the details on 
 that are still  being sorted out, I believe). However, I don't 
 believe that either Walter or Andrei  pays attention to 
 D.Learn, so if you want to bring it up for discussion, post  
 about it in the main newsgroup (not to mention, your post is 
 buried enough in  this thread that many who _do_ pay attention 
 to D.Learn wouldn't see it).

  This is a topic pulled from D.learn.
  
http://forum.dlang.org/thread/qyzvvlirbcklwjealnaa forum.dlang.org

  Quick brief overview: While trying to use opAssign to copy data 
(and keep arrays separate), one opAssign is being selected over 
the other. The first is for a reference (ref X) which does a 
buffer[] = rhs.buffer[] copy, while (X) for the temporaries the 
array is passed over, as buffer = rhs.buffer

  When adding changing (ref X) to (ref const X), it is calling the 
(X) which breaks my array separation when (ref const X) should 
work fine. (Afterall I'm promising not to change the data, not 
requiring it to be const).

"Era Scarecrow" <rtcvb32 yahoo.com> writes:

 On Saturday, May 05, 2012 05:50:26 Era Scarecrow wrote:
 Hmm maybe it should have a preference for Lvalue vs Rvalue... 
 So... Walter or Andrei?
 
  1. no match
  2. match with im­plicit con­ver­sions (Lvalue required)
  3. match with con­ver­sion to const (Lvalue required)
  4. match with im­plicit con­ver­sions
  5. match with con­ver­sion to const
  6. exact match



  Thinking about this, perhaps it should attempt the following 
order instead.

  (Not sure of the no match here)
  2. match with con­ver­sion to const (Lvalue required)
  3. match with im­plicit con­ver­sions (Lvalue required)
  4. match with con­ver­sion to const
  5. match with im­plicit con­ver­sions
  6. exact match
  7. no match - Templates attempted
  8. error?

  Trying the more restrictive ones first. You can convert mutable 
to const, but you can't turn it around without specific cast and 
knowledge. If you think about it too, very little code will 
likely be const, or ones that are const usually will be by 
themselves so ordering isn't going to be as important.