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digitalmars.D.learn - looking for V[string] workarounds

reply "Dan" <dbdavidson yahoo.com> writes:
Can the following be made to build and run, but keep the intent 
of what is shown. I realize it touches on several bugs related to 
const, postblit, and map - but I'm having trouble finding the 
magic combination. The idea is simply have assets store multiple 
series of data in a map indexed by the asset name.

Thanks,
Dan

import std.stdio;
struct Series {
   // REQUIRED - need to have no aliasing
   this(this) { data = data.dup;  }
   private double[] data;
}

struct Assets {
   this(this) { itemToSeries.dup; }
   // REQUIRED - want ctor to dup arg to ensure no aliasing
   this(const(Series[string]) source) {
     itemToSeries = source.dup;
   }
   private Series[string] itemToSeries;
}

void main() {
   auto data = [ "house" : Series([1,2,3.0])];
   auto assets = Assets(data);
   writeln(assets);
}
Mar 20 2013
parent reply =?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> writes:
On 03/20/2013 07:34 AM, Dan wrote:

 Can the following be made to build and run, but keep the intent of what
 is shown. I realize it touches on several bugs related to const,
 postblit, and map - but I'm having trouble finding the magic
 combination. The idea is simply have assets store multiple series of
 data in a map indexed by the asset name.

 Thanks,
 Dan

 import std.stdio;
 struct Series {
 // REQUIRED - need to have no aliasing
 this(this) { data = data.dup; }
 private double[] data;
 }

 struct Assets {
 this(this) { itemToSeries.dup; }
 // REQUIRED - want ctor to dup arg to ensure no aliasing
 this(const(Series[string]) source) {


The code compiles with 2.062 and an earlier version of 2.063 if you 
accept letting go of const-correctness there:

     this(Series[string] source) {


 itemToSeries = source.dup;
 }
 private Series[string] itemToSeries;
 }

 void main() {
 auto data = [ "house" : Series([1,2,3.0])];
 auto assets = Assets(data);
 writeln(assets);
 }


Ali
Mar 20 2013
parent reply "Dan" <dbdavidson yahoo.com> writes:
On Wednesday, 20 March 2013 at 17:11:02 UTC, Ali Çehreli wrote:

 The code compiles with 2.062 and an earlier version of 2.063 if 
 you accept letting go of const-correctness there:

     this(Series[string] source) {


Thanks Ali. But, removing const there then requires non-const 
instances to be passed in, due to const transitivity. So that 
requirement would ripple a change to all already const correct 
instances to now need to flip to non-const. I'm looking for a 
const correct solution. It should be doable ... I just have had 
no luck with it.

Thanks
Dan
Mar 20 2013
parent reply =?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> writes:
On 03/20/2013 10:24 AM, Dan wrote:

 On Wednesday, 20 March 2013 at 17:11:02 UTC, Ali Çehreli wrote:

 The code compiles with 2.062 and an earlier version of 2.063 if you
 accept letting go of const-correctness there:

 this(Series[string] source) {


 Thanks Ali. But, removing const there then requires non-const instances
 to be passed in, due to const transitivity. So that requirement would
 ripple a change to all already const correct instances to now need to
 flip to non-const. I'm looking for a const correct solution. It should
 be doable ... I just have had no luck with it.


In that case, brute force to the rescue (nc stands for non-const): :)

   this(const(Series[string]) source) {
       auto nc_source = cast(Series[string])source;
     itemToSeries = nc_source.dup;
   }

Ali
Mar 20 2013
parent "Dan" <dbdavidson yahoo.com> writes:
On Wednesday, 20 March 2013 at 17:44:16 UTC, Ali Çehreli wrote:

 In that case, brute force to the rescue (nc stands for 
 non-const): :)

   this(const(Series[string]) source) {
       auto nc_source = cast(Series[string])source;
     itemToSeries = nc_source.dup;
   }



Wow - that worked. Thanks! I hope it is safe.
Mar 20 2013