• Bill Baxter (7/7) Oct 16 2007 It seems like writef and many other functions got changed to vararg
• Walter Bright (8/14) Oct 16 2007 Yes. That makes them run much faster. Instead of interpreting the format...
• BCS (3/24) Oct 16 2007 If you want to known how many cases there are you can add a pragma(msg, ...

Bill Baxter <dnewsgroup billbaxter.com> writes:

It seems like writef and many other functions got changed to vararg 
templates in D2.x.

Doesn't this mean there will be a different instantiation of the writef 
template for every combination of arguments used to call it?  Sounds 
like it could lead to a lot of template bloat in D executables.  Is it a 
non-issue for some reason?

--bb

Walter Bright <newshound1 digitalmars.com> writes:

Bill Baxter wrote:
 It seems like writef and many other functions got changed to vararg 
 templates in D2.x.

Yes. That makes them run much faster. Instead of interpreting the format 
at runtime, each format gets custom code.

 Doesn't this mean there will be a different instantiation of the writef 
 template for every combination of arguments used to call it?

Yes - but I'll correct that for every *type* combination of arguments.

 Sounds like it could lead to a lot of template bloat in D executables.  Is it
a 
 non-issue for some reason?

The linker will remove duplicates. However, I think even in a large 
program, there won't be that many combinations. It also has the 
potential to *reduce* code bloat in small programs, as the unused 
formatting code won't be there.

BCS <ao pathlink.com> writes:

Reply to Walter,

 Bill Baxter wrote:
 
 It seems like writef and many other functions got changed to vararg
 templates in D2.x.
 

 Yes. That makes them run much faster. Instead of interpreting the
 format at runtime, each format gets custom code.
 
 Doesn't this mean there will be a different instantiation of the
 writef template for every combination of arguments used to call it?
 

 Yes - but I'll correct that for every *type* combination of arguments.
 
 Sounds like it could lead to a lot of template bloat in D
 executables.  Is it a non-issue for some reason?
 

 The linker will remove duplicates. However, I think even in a large
 program, there won't be that many combinations. It also has the
 potential to *reduce* code bloat in small programs, as the unused
 formatting code won't be there.
 

If you want to known how many cases there are you can add a pragma(msg,
formatTypeTupleTemplateWidgit!(args)) 
to wrightf and then filter the output for unique lines.