• LeoD (20/20) Jan 12 2007 Hi,
• Marcin Kuszczak (11/41) Jan 12 2007 Same here. They are not templated in D, but would be nice if they will.....
• Chris Nicholson-Sauls (19/48) Jan 12 2007 You can get this using typesafe variadic arguments:
• Marcin Kuszczak (15/44) Jan 12 2007 Interesting. I didn't know that. Could be useful, but to say true I thin...

LeoD <leo.dahlmann gmail.com> writes:

Hi,
can constructors be called implicit in D? Example:

class Foo
{
	this(int i)
	{

	}
}

void test(Foo f)
{

}

int main()
{
	test(100); // Here Foo.this(100); should get called

	return 0;
}


And why are there no templated constructors in D? Example:

this(T)(T parameter)
{

}

Marcin Kuszczak <aarti interia.pl> writes:

LeoD wrote:

 Hi,
 can constructors be called implicit in D? Example:
 
 class Foo
 {
 this(int i)
 {
 
 }
 }
 
 void test(Foo f)
 {
 
 }
 
 int main()
 {
 test(100); // Here Foo.this(100); should get called
 
 return 0;
 }
 

No. But I agree that it could be nice addition to D.

 
 And why are there no templated constructors in D? Example:
 
 this(T)(T parameter)
 {
 
 }

Same here. They are not templated in D, but would be nice if they will...

Hopefully Walter will add above features in future releases of DMD...

-- 
Regards
Marcin Kuszczak (Aarti_pl)
-------------------------------------
Ask me why I believe in Jesus - http://zapytaj.dlajezusa.pl (en/pl)
Doost (port of few Boost libraries) - http://www.dsource.org/projects/doost/
-------------------------------------

Chris Nicholson-Sauls <ibisbasenji gmail.com> writes:

LeoD wrote:
 Hi,
 can constructors be called implicit in D? Example:
 
 class Foo
 {
 	this(int i)
 	{
 
 	}
 }
 
 void test(Foo f)
 {
 
 }
 
 int main()
 {
 	test(100); // Here Foo.this(100); should get called
 
 	return 0;
 }

You can get this using typesafe variadic arguments:











See: http://digitalmars.com/d/function.html
Heading: Variadic Functions
Subheading: Typesafe Variadic Functions

 
 And why are there no templated constructors in D? Example:
 
 this(T)(T parameter)
 {
 
 }

Because constructors are not virtual... or at least that's the explanation
given in 
compiler errors with this.  Seems more like just a special case.  I was
actually a little 
bit disappointed myself, though the use cases seem to be pretty niche.

-- Chris Nicholson-Sauls

Marcin Kuszczak <aarti interia.pl> writes:

Chris Nicholson-Sauls wrote:

 LeoD wrote:
 Hi,
 can constructors be called implicit in D? Example:

 
 You can get this using typesafe variadic arguments:










 
 See: http://digitalmars.com/d/function.html
 Heading: Variadic Functions
 Subheading: Typesafe Variadic Functions
 

Interesting. I didn't know that. Could be useful, but to say true I think
that syntax/semantic is really strange... 


 
 And why are there no templated constructors in D? Example:
 


 
 Because constructors are not virtual... or at least that's the explanation
 given in
 compiler errors with this.  Seems more like just a special case.  I was
 actually a little bit disappointed myself, though the use cases seem to be
 pretty niche.

As I know constructors in C++ are also not virtual, but they can be
templated. I don't get connection here... 

It could be useful for variant classes which could be constructed with
different types. I couldn't translate Boost::Any well  because of that
problem (there is enhancement request on bugzilla).


-- 
Regards
Marcin Kuszczak (Aarti_pl)
-------------------------------------
Ask me why I believe in Jesus - http://zapytaj.dlajezusa.pl (en/pl)
Doost (port of few Boost libraries) - http://www.dsource.org/projects/doost/
-------------------------------------