bearophile wrote:
> Piotr Szturmaj:
>
>> -- for CSV:
>>
>> alias Tuple!(int, string, int) IdNameAge;
>>
>> foreach (csvLine; csvFile.byCSVLine)
>> {
>>       auto line = to!IdNameAge(splitter(csvLine, ';'));
>>       // line here is a tuple converted from runtime csv fields
>> }
>
> See here the answer 23 by Andrei Alexandrescu to a sub-request of mine:
> http://d.puremagic.com/issues/show_bug.cgi?id=6365#c23

"Too much magic" argument is for dmd implementation, but it may be implemented in std.conv.

2011/10/20 Piotr Szturmaj <bncrbme@jadamspam.pl>:
> Robert Jacques wrote:
>>
>> On Wed, 19 Oct 2011 14:16:31 -0400, Piotr Szturmaj <bncrbme@jadamspam.pl> wrote:
>>>
>>> bearophile wrote:
>>>>
>>>> Piotr Szturmaj:
>>>>
>>>>> I have written a simple conversion template for tuples, structs and classes:
>>>>
>>>> Do you have some use case to show me?
>>>
>>> class C
>>> {
>>> int i;
>>> string s;
>>> }
>>>
>>> struct S
>>> {
>>> string s;
>>> float f;
>>> }
>>>
>>> auto c = to!C(S("5", 2.5f));
>>> assert(c.i == 5 && c.s == "2.5");
>>>
>>
>> So C's s field maps to S's f field, not it's s field? That seems unintuitive and bug prone.

I'm agree with bearophile.

> This isn't name to name mapping but field to field mapping.

I think std.conv.to should provide the *safe natural conversion*. Field-to-field conversion seems not natural, and it is called 'Structural conversion'.

Kenji Hara

On 10/20/11 6:53 AM, kenji hara wrote:
> I think std.conv.to should provide the *safe natural conversion*.
> Field-to-field conversion seems not natural, and it is called
> 'Structural conversion'.

I agree. We could, however, add std.conv.structuralCast.

Andrei

That would be great! that ides evaluates to:
--boilerplate;

On Thu, Oct 20, 2011 at 7:02 PM, Andrei Alexandrescu <SeeWebsiteForEmail@erdani.org> wrote:
> On 10/20/11 6:53 AM, kenji hara wrote:
>>
>> I think std.conv.to should provide the *safe natural conversion*. Field-to-field conversion seems not natural, and it is called 'Structural conversion'.
>
> I agree. We could, however, add std.conv.structuralCast.
>
> Andrei
>