Generic structural recursion
schveiguy at gmail.com
Thu Jan 27 14:47:25 UTC 2022
On 1/26/22 2:57 PM, H. S. Teoh wrote:
> On Wed, Jan 26, 2022 at 02:06:18PM -0500, Steven Schveighoffer via Digitalmars-d wrote:
>> auto interpolate(alias fn, X : double)(ref X val1, ref X val2)
>> static if(is(typeof(fn(val1, val2)))) return fn(val1, val2);
>> auto interpolate(alias fn, X)(ref X val1, ref X val2) if (is(X == struct))
>> // loop and recurse
> That's what I had, but the problem is that the number of X arguments
> differs from function to function. So I'd have to duplicate the
> recursion part for each number of arguments, which is bad because
> there's a chance I might change the recursion in the unary version and
> forget to update it in the binary/ternary/etc. version.
Well, this is what I would do then.
auto interpolateImpl(alias fn, Vals...)(ref Vals vals) if (is(Vals ==
// handle all the other specific types etc.
auto interpolate(alias fn, Vals...)(ref Vals vals) if (allSameType!Vals)
Then the only complex one is the one for aggregates.
More information about the Digitalmars-d