• Aarti_pl <aarti interia.pl> Jan 15 2008
• Bjoern <nanali nospam-wanadoo.fr> Jan 15 2008
• downs <default_357-line yahoo.de> Jan 15 2008
• Aarti_pl <aarti interia.pl> Jan 15 2008
• BCS <BCS pathlink.com> Jan 15 2008

Aarti_pl <aarti interia.pl> writes:

Any comments on this? Probably error, but maybe someone wants to add 
something...

--------

void pattern(T)(T v) {}

T pattern(T)() {return T.init;}

void main() {
     pattern!(int)(5);
}

---------

Above code results in compile time error:

quicktest.d(6): template instance pattern!(int) matches more than one 
template declaration, pattern(T) and pattern(T)
quicktest.d(6): Error: template instance 'pattern!(int)' is not a variable
quicktest.d(6): Error: function expected before (), not pattern!(int) of 
type int

---------

As you see it is standard D setter/getter approach with templates.

What's more interesting, when we call pattern template function with 
IFTI it calls proper function:

pattern(5); //calls setter

but:
pattern; // is error

BTW: I hope that in DMD 2.0
writefln;
will be also allowed. Currently it doesn't work - you have to write 
writefln();

BR
Marcin Kuszczak
(aarti_pl)

Bjoern <nanali nospam-wanadoo.fr> writes:

Aarti_pl schrieb:
 Any comments on this? Probably error, but maybe someone wants to add 
 something...
 
 --------
 
 void pattern(T)(T v) {}
 
 T pattern(T)() {return T.init;}
 
 void main() {
     pattern!(int)(5);
 }
 
 ---------
 
 Above code results in compile time error:
 
 quicktest.d(6): template instance pattern!(int) matches more than one 
 template declaration, pattern(T) and pattern(T)
 quicktest.d(6): Error: template instance 'pattern!(int)' is not a variable
 quicktest.d(6): Error: function expected before (), not pattern!(int) of 
 type int
 
 ---------
 
 As you see it is standard D setter/getter approach with templates.
 
 What's more interesting, when we call pattern template function with 
 IFTI it calls proper function:
 
 pattern(5); //calls setter
 
 but:
 pattern; // is error
 
 BTW: I hope that in DMD 2.0
 writefln;
 will be also allowed. Currently it doesn't work - you have to write 
 writefln();
 
 BR
 Marcin Kuszczak
 (aarti_pl)


Sorry untested and just an idea :(
What happens when you use :
T pattern(T)(out T t) {return t;}
instead of
T pattern(T)() {return T.init;}

Bjoern

downs <default_357-line yahoo.de> writes:

Aarti_pl wrote:
 Any comments on this? Probably error, but maybe someone wants to add
 something...
 
 --------
 
 void pattern(T)(T v) {}
 
 T pattern(T)() {return T.init;}
 
 void main() {
     pattern!(int)(5);
 }
 
 ---------


There's a dirty, dirty but working work-around for this :)

T pattern(T)() { return T.init; }
void pattern(T, BOGUS=void)(T v) { }

then just use IFTI for the second one.

 --downs

Aarti_pl <aarti interia.pl> writes:

downs pisze:
 Aarti_pl wrote:
 Any comments on this? Probably error, but maybe someone wants to add
 something...

 --------

 void pattern(T)(T v) {}

 T pattern(T)() {return T.init;}

 void main() {
     pattern!(int)(5);
 }

 ---------


 There's a dirty, dirty but working work-around for this :)
 
 T pattern(T)() { return T.init; }
 void pattern(T, BOGUS=void)(T v) { }
 
 then just use IFTI for the second one.
 
  --downs


Thanks! Nice to know it!

BR
Marcin Kuszczak
(aarti_pl)

BCS <BCS pathlink.com> writes:

Aarti_pl wrote:
 Any comments on this? Probably error, but maybe someone wants to add 
 something...
 
 --------
 
 void pattern(T)(T v) {}
 
 T pattern(T)() {return T.init;}
 
 void main() {
     pattern!(int)(5);
 }
 
 ---------
 
 Above code results in compile time error:
 
 quicktest.d(6): template instance pattern!(int) matches more than one 
 template declaration, pattern(T) and pattern(T)
 quicktest.d(6): Error: template instance 'pattern!(int)' is not a variable
 quicktest.d(6): Error: function expected before (), not pattern!(int) of 
 type int
 


the issue is more noticeable in this form

template pattern(T) { void pattern(T v) {} }
template pattern(T) { T pattern() {return T.init;} }

void main() {
     pattern!(int)(5);
}

DMD can't pick witch template to do. My thoughts on fixing this would be 
to let this work:

template pattern(T)
{
	void pattern(T v) {}
	T pattern() {return T.init;}
}