Hello,

For tuples, does the fieldNames property have a 1-1 correspondence with the Types property?

It appears that way in my testing:

alias MyData = Tuple!(string,"a",int,"b");
foreach (i, type; MyData.Types){
    writeln (MyData.fieldNames[i]," ",type.stringof);
    // a string
    // b int
}

But I can't figure out for sure from the documentation:

alias fieldNames = staticMap!(extractName, fieldSpecs);
alias Types = staticMap!(extractType, fieldSpecs);

Thanks,

Jordan

On Thursday, 30 June 2016 at 21:53:42 UTC, Jordan Wilson wrote:
> Hello,
>
> For tuples, does the fieldNames property have a 1-1 correspondence with the Types property?
>
> It appears that way in my testing:
>
> alias MyData = Tuple!(string,"a",int,"b");
> foreach (i, type; MyData.Types){
>     writeln (MyData.fieldNames[i]," ",type.stringof);
>     // a string
>     // b int
> }
>
> But I can't figure out for sure from the documentation:
>
> alias fieldNames = staticMap!(extractName, fieldSpecs);
> alias Types = staticMap!(extractType, fieldSpecs);
>
> Thanks,
>
> Jordan

static map (and map in general) is a 1:1 correspondence, so yes.

On Thursday, 30 June 2016 at 21:53:42 UTC, Jordan Wilson wrote:
> Hello,
>
> For tuples, does the fieldNames property have a 1-1 correspondence with the Types property?
>
> It appears that way in my testing:
>
> alias MyData = Tuple!(string,"a",int,"b");
> foreach (i, type; MyData.Types){
>     writeln (MyData.fieldNames[i]," ",type.stringof);
>     // a string
>     // b int
> }
>
> But I can't figure out for sure from the documentation:
>
> alias fieldNames = staticMap!(extractName, fieldSpecs);
> alias Types = staticMap!(extractType, fieldSpecs);
>
> Thanks,
>
> Jordan

It's an implementation detail but I wouldn't expect the order to ever change.