Given this code for CTFE on a string array:

enum E {one, two}
enum string[] fields = [EnumMembers!E].to!(string[]);

string print(string[] fields)
{
    string s;
    foreach(string field; fields)
    {
        s ~= field.toUpper ~ ", ";
    }
    return s;
}

pragma(msg, print(["one", "two"]));
pragma(msg, print(fields));

I am trying to understand why the first pragma produces correct output but the second one fails in std.string.toUpper (cannot interpret result ~= c at compile-time)?

On Thu, Aug 30, 2012 at 2:13 AM, cal <callumenator@gmail.com> wrote:
> Given this code for CTFE on a string array:
>
> enum E {one, two}
> enum string[] fields = [EnumMembers!E].to!(string[]);
>
> string print(string[] fields)
> {
>     string s;
>     foreach(string field; fields)
>     {
>         s ~= field.toUpper ~ ", ";
>     }
>     return s;
> }
>
> pragma(msg, print(["one", "two"]));
> pragma(msg, print(fields));
>
> I am trying to understand why the first pragma produces correct output but the second one fails in std.string.toUpper (cannot interpret result ~= c at compile-time)?
>

And with no UFCS ? Did you try s ~= toUpper(field) ~ ", ";

On Thursday, 30 August 2012 at 05:26:52 UTC, Philippe Sigaud wrote:
> And with no UFCS ? Did you try s ~= toUpper(field) ~ ", ";

Yeah with or without UFCS, the second one fails.

On 2012-08-30 02:13, cal wrote:
> Given this code for CTFE on a string array:
>
> enum E {one, two}
> enum string[] fields = [EnumMembers!E].to!(string[]);
>
> string print(string[] fields)
> {
>      string s;
>      foreach(string field; fields)
>      {
>          s ~= field.toUpper ~ ", ";
>      }
>      return s;
> }
>
> pragma(msg, print(["one", "two"]));
> pragma(msg, print(fields));
>
> I am trying to understand why the first pragma produces correct output
> but the second one fails in std.string.toUpper (cannot interpret result
> ~= c at compile-time)?

It works for me. DMD 2.060 Mac OS X.

-- 
/Jacob Carlborg

On 2012-08-30 08:28, Jacob Carlborg wrote:

> It works for me. DMD 2.060 Mac OS X.

Oh, it does not. If I replace:

enum string[] fields = [EnumMembers!E].to!(string[]);

With:

enum string[] fields = ["one", "two"];

It works.

-- 
/Jacob Carlborg

On Thursday, 30 August 2012 at 06:30:50 UTC, Jacob Carlborg wrote:
> On 2012-08-30 08:28, Jacob Carlborg wrote:
>
>> It works for me. DMD 2.060 Mac OS X.
>
> Oh, it does not. If I replace:
>
> enum string[] fields = [EnumMembers!E].to!(string[]);
>
> With:
>
> enum string[] fields = ["one", "two"];
>
> It works.

Yeah its weird because:

enum string[] literalFields = ["one", "two"];
enum string[] enumFields = [EnumMembers!E].to!(string[]);

pragma(msg, literalFields[0] == enumFields[0]);

prints true, but toUpper works on the first and not the second

On Thursday, 30 August 2012 at 17:38:48 UTC, cal wrote:
> On Thursday, 30 August 2012 at 06:30:50 UTC, Jacob Carlborg wrote:

Replacing string[] with dstring[] for EnumMembers triggers a DMD bug, so I guess the CTFE interpreter is buggy even in the string[] case.

Filed http://d.puremagic.com/issues/show_bug.cgi?id=8601