No comments by anyone? Should be harmless -- may just merge in a few ...

We might (?) need a few more changes on our side:

inst/include/Rcpp/sugar/functions/complex.h28:# define RCPP_HYPOT ::Rf_pythaginst/include/Rcpp/sugar/undoRmath.h110:#undef pythaginst/include/Rcpp/Rmath.h222:    inline double pythag(double a, double b)        { return ::Rf_pythag(a, b); }

I think the bit inundoRmath.h can stay, but we might want to tweak what we have incomplex.h:

kevin@cdrv:~/r/pkg/Rcpp [rng-state]$ ag -Q "RCPP_HYPOT"inst/include/Rcpp/sugar/functions/complex.h26:# define RCPP_HYPOT ::hypot28:# define RCPP_HYPOT ::Rf_pythag83:             y.r = ::log( RCPP_HYPOT( x.r, x.i ) );90:         if( (mag = RCPP_HYPOT(z.r, z.i)) == 0.0)144:    t1 = 0.5 * RCPP_HYPOT(x + 1, y);145:    t2 = 0.5 * RCPP_HYPOT(x - 1, y);

If I understand correctly, R removed that function because C99 now defines::hypot() and so R doesn't need to provide its own definition. (If I understand correctly,Rf_pythag() was R's own definition of::hypot(), for platforms that didn't provide it back in the day)

That said, if everything compiles and checks okay we can probably leave it as is?

There is indeed a bit more. You first catch is good: RCPP_HYPOT is conditionally defined with a now-dead fallback. Theundef is harmless. Theinline we can just comment out as well.

The use ofRCPP_HYPOT may need a second look as RCPP_HYPOT now has no fallback. Question is then ... would#ifdef HAVE_HYPOT ever not be true? And if so, shall we just emit a warning there?

man 3 hypot points to C99, POSIX.1-2001, POSIX.1-2008. Good enough?

Also:

edd@rob:~$ grep HAVE_HYPOT~/svn/r-devel/config.status S["RMATH_HAVE_HYPOT"]="# define HAVE_HYPOT 1"D["HAVE_HYPOT"]=" 1"edd@rob:~$

The cleanest may just be to rewritecomplex.h and do away withRCPP_HYPOT in favour of::hypot. Let me pile that on later today.

I thinkHAVE_HYPOT is effectively always true since (as you pointed out) it's defined by the C99 standard and I think R requires C99 or greater during compilation of R + extensions.

@kevinushey That was an excellent catch. I maded some changes, when you have moment, could you peruse?

LGTM -- thanks for taking care of this!