I have a library with one template function in it

template array_case(T)
{

 void array_change_key_case ( T[ char [] ] map)
 {

  foreach ( inout char [] keys;map.keys )
  {

   keys = std.string.tolower(keys );

  }


 }

}



However when I build the lib, I get the error

Symbol Undefined _D3phd5array13array_case_Aa21array_change_key_caseFHAaAaZv

If i eliminate the template and just make them functions it works fine.

What is the rule with templates in libraries, I have to call the template somewhere in the code for it to generate stuff or ?


Charlie

Charlie wrote:
> I have a library with one template function in it
> 
> template array_case(T)
> {
> 
>  void array_change_key_case ( T[ char [] ] map)
>  {
> 
>   foreach ( inout char [] keys;map.keys )
>   {
> 
>    keys = std.string.tolower(keys );
> 
>   }
> 
> 
>  }
> 
> }
> 
> 
> 
> However when I build the lib, I get the error
> 
> Symbol Undefined _D3phd5array13array_case_Aa21array_change_key_caseFHAaAaZv
> 
> If i eliminate the template and just make them functions it works fine.
> 
> What is the rule with templates in libraries, I have to call the template
> somewhere in the code for it to generate stuff or ?
> 
> 
> Charlie
> 
> 

Is the template in a file by itself?

I reported this problem earlier; see post "Hair-pulling, D, and Optlink"

Walter game the solution for dealing with this very real shortcoming in OMF libraries containing templates:

http://www.digitalmars.com/drn-bin/wwwnews?digitalmars.D/23701

I imagine that's what your problem was.

-JJR

Hey John,

That did work thanks :).  I remember reading something about this but forget the title.

This is pretty rough , I wonder though is OMF the only format that suffers from this ?  I don't know enough about C++ templates to guess how they do it .

Charlie

"John Reimer" <brk_6502@yahoo.com> wrote in message news:d7t782$a6t$1@digitaldaemon.com...
> Charlie wrote:
> > I have a library with one template function in it
> >
> > template array_case(T)
> > {
> >
> >  void array_change_key_case ( T[ char [] ] map)
> >  {
> >
> >   foreach ( inout char [] keys;map.keys )
> >   {
> >
> >    keys = std.string.tolower(keys );
> >
> >   }
> >
> >
> >  }
> >
> > }
> >
> >
> >
> > However when I build the lib, I get the error
> >
> > Symbol Undefined
_D3phd5array13array_case_Aa21array_change_key_caseFHAaAaZv
> >
> > If i eliminate the template and just make them functions it works fine.
> >
> > What is the rule with templates in libraries, I have to call the
template
> > somewhere in the code for it to generate stuff or ?
> >
> >
> > Charlie
> >
> >
>
> Is the template in a file by itself?
>
> I reported this problem earlier; see post "Hair-pulling, D, and Optlink"
>
> Walter game the solution for dealing with this very real shortcoming in OMF libraries containing templates:
>
> http://www.digitalmars.com/drn-bin/wwwnews?digitalmars.D/23701
>
> I imagine that's what your problem was.
>
> -JJR

An 'slightly' better soloution is to put that int* call in a mixin

int comdatKludge = 0;
template kludge ()
{

 int * kludge = &comdatKludge;

}

into the library, then the client just calls

mixin kludge;


"John Reimer" <brk_6502@yahoo.com> wrote in message news:d7t782$a6t$1@digitaldaemon.com...
> Charlie wrote:
> > I have a library with one template function in it
> >
> > template array_case(T)
> > {
> >
> >  void array_change_key_case ( T[ char [] ] map)
> >  {
> >
> >   foreach ( inout char [] keys;map.keys )
> >   {
> >
> >    keys = std.string.tolower(keys );
> >
> >   }
> >
> >
> >  }
> >
> > }
> >
> >
> >
> > However when I build the lib, I get the error
> >
> > Symbol Undefined
_D3phd5array13array_case_Aa21array_change_key_caseFHAaAaZv
> >
> > If i eliminate the template and just make them functions it works fine.
> >
> > What is the rule with templates in libraries, I have to call the
template
> > somewhere in the code for it to generate stuff or ?
> >
> >
> > Charlie
> >
> >
>
> Is the template in a file by itself?
>
> I reported this problem earlier; see post "Hair-pulling, D, and Optlink"
>
> Walter game the solution for dealing with this very real shortcoming in OMF libraries containing templates:
>
> http://www.digitalmars.com/drn-bin/wwwnews?digitalmars.D/23701
>
> I imagine that's what your problem was.
>
> -JJR

In article <d7takf$c4j$1@digitaldaemon.com>, Charlie says...
>
>An 'slightly' better soloution is to put that int* call in a mixin
>
>int comdatKludge = 0;
>template kludge ()
>{
>
> int * kludge = &comdatKludge;
>
>}
>
>into the library, then the client just calls
>
>mixin kludge;

Hopefully Walter is able to find a fix for this problem at some point. I've added some more information to http://www.prowiki.org/wiki4d/wiki.cgi?DocComments/Template to help explain the problem and some possible solutions (basically, I cut-and-pasted some of these posts into the Wiki).

jcc7

Charlie wrote:
> An 'slightly' better soloution is to put that int* call in a mixin
> 
> int comdatKludge = 0;
> template kludge ()
> {
> 
>  int * kludge = &comdatKludge;
> 
> }
> 
> into the library, then the client just calls
> 
> mixin kludge;
> 
> 

Yeah... that does look a little cleaner! Nice one!

Although it does advertise the fact that their is a kludge! :-)

-JJR