On Thursday, 17 May 2018 at 16:27:48 UTC, Paul Backus wrote:
On Thursday, 17 May 2018 at 15:25:37 UTC, Sjoerd Nijboer wrote:
I want to make a template mixin that is able to cast one of
these generic structs to the other explicitly. I have a bunch
of these structs and therefore I thought it would make sense
to do it by template mixin. I just don't know what language or
library features I need to use and how to apply them.
It sounds like you want to overload opCast:
https://dlang.org/spec/operatoroverloading.html#cast
Something like:
`
Foo!T opCast(U)(Foo!U old)
if (isImplicitlyConvertible!(T, U))
{
return Foo!T(old.t);
}
Foo!T opCast(UTemplate, U)(UTemplate!U old)
if (isImplicitlyConvertible!(T, U) && isNumerical!U)
{
return Foo!T(old.t);
}
`
But then how do you put this into a mixin template so I can write
something like
`
struct Foo(T)
if(isNumerical(T))
{
mixin castingRules(typeof(this) T);
}
`
