The following crashes on writeln, but looks reasonable. Is some form of initializing ctor required for RateCurve?

import std.datetime;
import std.range;
import std.stdio;

struct DateRate {
  Date date;
  double value = 0.0;
}

struct RateCurve {
  private immutable(DateRate)[] _data;
}

struct CFS {
  double initialValue;
  RateCurve growth;
}

void main() {
  auto s = CFS(1.0);
  // auto s = CFS(1.0, RateCurve()); // crashes
  // auto s = CFS(1.0, RateCurve([])); // works
  writeln(s);
}

Thanks
Dan

On 10/31/2013 08:29 PM, Daniel Davidson wrote:
> The following crashes on writeln, but looks reasonable. Is some form of
> initializing ctor required for RateCurve?
>
> import std.datetime;
> import std.range;
> import std.stdio;
>
> struct DateRate {
>    Date date;
>    double value = 0.0;
> }
>
> struct RateCurve {
>    private immutable(DateRate)[] _data;
> }
>
> struct CFS {
>    double initialValue;
>    RateCurve growth;
> }
>
> void main() {
>    auto s = CFS(1.0);
>    // auto s = CFS(1.0, RateCurve()); // crashes
>    // auto s = CFS(1.0, RateCurve([])); // works
>    writeln(s);
> }
>
> Thanks
> Dan

You are not going to like my answer but this may be the 16-byte struct bug. Add something to RateCurve and your code works fine... :-/

struct RateCurve {
  private immutable(DateRate)[] _data;
    ubyte b;  // <-- ADDED
}

Ali

On Friday, 1 November 2013 at 04:26:25 UTC, Ali Çehreli wrote:
>
> You are not going to like my answer but this may be the 16-byte struct bug. Add something to RateCurve and your code works fine... :-/
>
> struct RateCurve {
>   private immutable(DateRate)[] _data;
>     ubyte b;  // <-- ADDED
> }
>

I appreciate and hate the answer :-). I've had a variant of this code working for a while. The previous version had DateRate[] instead of immutable(DateRate)[]. Since DateRate has no immutable aliasing I was trying to go for a more string-like immutable by design class.

My hope is that is not the problem, or if it is it rears its head only in the context of initializers that leave that member empty. In this example if I provided `CFS(1.0, RateCurve([]));`  as the initializer then it worked fine.

What exactly is the 16-byte bug? I can't imagine 16-byte structs are generally a problem.

Thanks,
Dan