Fixing algorithm.h for icc (closes #640)

[dcdillon]

Now we have RCPP_CONSTEXPR_VAR and RCPP_CONSTEXPR_FUNC which are defined properly.

[eddelbuettel]

Paging @coatless as the white knight in shining armour ... and access to icc. Can you check this, please?

[coatless]

Passes with flying colors outside of the other warning not related to the algorithm.h

Date.cpp(642): warning #437: reference to local variable of enclosing function is not allowed
                      2 * sizeof *sp + 4 * TZ_MAX_TIMES];
                                  ^

[kevinushey]

Is that icc warning in Date.cpp something real, or can we just ignore it?

[eddelbuettel]

It annoyed me too, but I checked against current R-devel and it has basically still the identical code (though they renamed the union u to union u_t). So I'd through my arms up in the air.

Lines 375+ from ~/svn/r-devel/src/extra/tzone/localtime.c, current as of a few hours ago:

static int
tzload(const char * name, struct state * const sp, const int doextend)
{
    const char * p;
    int	 i;
    int	 fid;
    ssize_t nread;
    typedef union {
	struct tzhead  tzhead;
	char  buf[2 * sizeof(struct tzhead) + 
		  2 * sizeof *sp + 4 * TZ_MAX_TIMES];
    } u_t;