On Friday, 21 April 2017 at 16:31:37 UTC, H. S. Teoh wrote:
On Fri, Apr 21, 2017 at 04:16:30PM +0000, David Sanders via
Digitalmars-d-learn wrote:
I'm trying to do algebra with types ala
http://chris-taylor.github.io/blog/2013/02/10/the-algebra-of-algebraic-data-types/
Below you will find my attempts at "adding" types in D. I've
outlined the parts I'm having trouble with using block
comments.
1) How do I figure out whether a type is an instantiation of
std.variant.Algebraic?
2) If the type is Algebraic, how do I capture its AllowedTypes?
[...]
static if (is(T : Algebraic!(U...), U))
{
// U now refers to the argument to Algbraic.
}
--T
There's also a private `isAlgebraic` template[1]. Is there any
reason why we couldn't just make this public?
1. https://github.com/dlang/phobos/blob/master/std/variant.d#L2236
