On 2010-06-28 14:14, Philippe Sigaud wrote:
On Mon, Jun 28, 2010 at 10:56, Jacob Carlborg <[email protected]
<mailto:[email protected]>> wrote:
Something to keep in mind: as of 2.04x (.045? maybe), the way UTF-8 /
UTF-32 is managed was changed. "asd" is an array of immutable(dchar),
not imutable(char). At least DMD tells me that its element type is 'dchar'.
So your function can be done this way in D2:
void foo(T,U)(in T[] a, U b) if (is(U : Unqual!T)) // that compiles only
if b can be cast to A
{
writeln(a,b);
}
"asd".foo('s'); // prints "asds".
is(U == Unqual!T) does not work, for U is 'char' while Unqual!T is 'dchar'.
More generally, using ranges and not arrays, the template becomes a bit
more heavy:
void foo(Range,Elem)(in Range range, Elem elem)
if (isInputRange!Range && is(Elem : Unqual!(ElementType!Range)))
{
...
}
I don't think I understand what you're showing here. How would I
strip off the const/immutable with a template ?
Hmmm...
* plays with is expressions *
This seems to work:
template UnConst(T)
{
static if (is(T t == const U, U)) // that is: 'if T is a 'const U',
for some U'
alias U UnConst; // then give me the U,
(ie, T without a const)
else
alias T UnConst; // else give me the
(original) T
}
template UnImmutable(T)
{
static if (is(T t == immutable U, U)) // 'if T is an 'immutable U',
for some U'
alias U UnImmutable;
else
alias T UnImmutable;
}
test:
void main() {
alias const int Int;
writeln(UnConst!Int.stringof);
writeln(Int.stringof);
writeln(UnConst!int.stringof);
writeln(UnConst!(const int).stringof);
writeln(UnConst!(immutable int).stringof);
alias immutable int IInt;
writeln(UnConst!IInt.stringof);
writeln(IInt.stringof);
writeln(UnImmutable!int.stringof);
writeln(UnImmutable!(const int).stringof);
writeln(UnImmutable!(immutable int).stringof);
}
Philippe
Hmm, now I don't know what I'm doing, I thought you could do something
like this:
template Char (T)
{
alias T Char;
}
void foo (T) (Char!(T) b)
{
}
void main ()
{
foo('s');
}
--
/Jacob Carlborg
