• dennis luehring <dl.soluz gmx.net> May 29 2007
• BCS <BCS pathlink.com> May 29 2007
• Reiner Pope <some address.com> May 29 2007
• Daniel Keep <daniel.keep.lists gmail.com> May 29 2007
• Don Clugston <dac nospam.com.au> May 29 2007

dennis luehring <dl.soluz gmx.net> writes:

what is the reason for allowing this

template test(char[] bla)
{
...
}


but not

template test(int[] bla)
{
...
}

or other bultin(own) types?

ciao dennis

BCS <BCS pathlink.com> writes:

dennis luehring wrote:
 what is the reason for allowing this
 
 template test(char[] bla)
 {
 ....
 }
 
 
 but not
 
 template test(int[] bla)
 {
 ....
 }
 
 or other bultin(own) types?
 
 ciao dennis



I'm with you on this.

see this:
http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D&article_id=53939

Reiner Pope <some address.com> writes:

dennis luehring wrote:
 what is the reason for allowing this
 
 template test(char[] bla)
 {
 ...
 }
 
 
 but not
 
 template test(int[] bla)
 {
 ...
 }
 
 or other bultin(own) types?
 
 ciao dennis


I agree that it doesn't make sense, but you can do this hack:

template test(T...)
{
     static assert(is(typeof(T[0]) == int[]));
     const int[] bla = T[0];
}


    -- Reiner

Daniel Keep <daniel.keep.lists gmail.com> writes:

dennis luehring wrote:
 what is the reason for allowing this
 
 template test(char[] bla)
 {
 ....
 }
 
 
 but not
 
 template test(int[] bla)
 {
 ....
 }
 
 or other bultin(own) types?
 
 ciao dennis


I think it's because arguments to a template become part of its mangled
name.  Integers and floats are easy, as are actual strings, but to
support arbitrary types, Walter would either need some kind of generic
serialisation setup, or find a new way of mangling templates.

At least, that's how I understand it :)

	-- Daniel

-- 
int getRandomNumber()
{
    return 4; // chosen by fair dice roll.
              // guaranteed to be random.
}

http://xkcd.com/

v2sw5+8Yhw5ln4+5pr6OFPma8u6+7Lw4Tm6+7l6+7D
i28a2Xs3MSr2e4/6+7t4TNSMb6HTOp5en5g6RAHCP  http://hackerkey.com/

Don Clugston <dac nospam.com.au> writes:

Daniel Keep wrote:
 
 dennis luehring wrote:
 what is the reason for allowing this

 template test(char[] bla)
 {
 ....
 }


 but not

 template test(int[] bla)
 {
 ....
 }

 or other bultin(own) types?

 ciao dennis


 I think it's because arguments to a template become part of its mangled
 name.


  Integers and floats are easy, as are actual strings, but to
 support arbitrary types, Walter would either need some kind of generic
 serialisation setup, or find a new way of mangling templates.


That's not much of an issue. In fact, if you look at the ABI page, 
you'll see that the mangling scheme almost supports arbitrary types already.

TemplateArg:
     T Type
     V Type Value
     S LName
Any type which can be a type template parameter, and which has literals, 
could also be a value parameter.

The problem is that the mangled names become too long, which makes bad 
things happen (eg, the obj file format imposes a maximum identifier 
length of ~ 3kB).
There a few types (int[], short[] ubyte[]) which are essentially 
identical to the permitted dchar[], wchar[], char[], and could trivially 
be permitted.

CTFE has drastically reduced the number of cases where it would be 
useful, though.