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)

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

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

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)

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;}
}