On Friday, 24 March 2017 at 20:43:18 UTC, Dmitry Olshansky wrote:
On 3/24/17 12:24 AM, Yuxuan Shui wrote:
So I was trying to make my template take a value parameter,
whose type
is also a parameter to the template. e.g.:
template A(Char[] str, Char);
But dmd complains about 'Char' being undefined. I have to
write:
template A(Char, Char[] str);
Which is inconvenient, because now 'Char' can't be deduced by
the compiler.
Can we make the first case work?
How about this?
template A(alias str)
if(is(typeof(str) : Char[], Char)){
alias Char = typeof(str[0]);
// ...
}
Yes. This is what I ended up doing
(https://github.com/yshui/sdpc/blob/master/sdpc/parsers.d#L45).
One problem of this is that 'str' is not longer restricted to be
a compile time value. Which is probably fine, but kind of makes
me uncomfortable.
In general it's sometimes possible to do the deduction w/o
introducing more template arguments.
---
Dmitry Olshansky
