Template type parameters with their own type parameters
Peter Lundgren
lundgrpb at rose-hulman.edu
Sat Mar 5 20:42:17 PST 2011
== Quote from spir (denis.spir at gmail.com)'s article
> On 03/05/2011 04:02 AM, Peter Lundgren wrote:
> > I have a function that I think should look something like this:
> >
> > MyStruct!T myFunc(T)(MyStruct!T x, ...) {
> > ...
> > return MyStruct!T(...);
> > }
> >
> > and the closest I can get to is:
> >
> > T myFunc(T)(T x, ...) {
> > ...
> > return T(...);
> > }
> >
> > which works, but doesn't make clear the intended use and gets in the way of
> > overloading. How can I express the intent of the first version.
> Maybe I do not exactly understand your problem; anyway, the following runs fine
> by me:
> struct S (T) {
> T v;
> }
> S!T inc (T) (S!T s) {
> return S!T(s.v + 1);
> }
> unittest {
> auto s1 = S!int(1);
> auto s2 = inc(s1);
> assert ( s2.v == 2 );
> }
> Could you provide (1) context (2) example (3) errors?
> Denis
Thanks for the help. I'd convinced myself that it didn't work and missed the
actual problem. I was mixing template type and template value parameters. What I
really wanted was this:
MyStruct!v myFunc(string v)(MyStruct!v x, ...) {
...
return MyStruct!v(...);
}
More information about the Digitalmars-d-learn
mailing list