Re: proposal for new assignment operators

[James Rogers <jimmaureenrogers@att.net>]

Hyman Rosen <hyrosen@mail.com> wrote in 
news:1057672755.789189@master.nyc.kbcfp.com:

> Template parameters are used in the linkage of instantiated templates
> (loosely speaking, the parameters are interpolated into the name of the
> instantiation), and template arguments can be constant expressions.
> Allowing floating-point parameters would lead to questions of equivalence
> of instantiations. In my opinion that's not such a terrible burden, and I
> would have allowed it, but the standard doesn't. Some compilers offer it
> as an extension.
> 
> As a sample of the problem, consider
>      template <float X> char *f() { static char c; return &c; }
>      bool b = f<1./3.>() == f<1./6.+1./6.>();
> How do you specify what the value of 'b' should be?
> 

Interesting.

I suppose part of the problem can be the algorithm for interpolation
of the parameter(s) into an instance name. Does the standard specify
this algorithm, or is that 'implementation defined'? If the standard
does not specify the interpolation algorithm I would expect object
files from different compilers to be incompatible with each other
when instantiating a template from a commonly referenced header file.

Are the parameters also available within the body of the template
for logic purposes?

Jim Rogers