#include <R.h>
#include <Rinternals.h>

static void addone(double *x, int *nx, double *val, int *nv)
{
    if (nx[0] == nv[0]) {
	int n, i;

	n = nx[0];
	for (i = 0; i < n; i++)
	    val[i] = x[i] + 1.0;
    }
    else error("argument and value lengths do not match.");
}

SEXP addoneDotCall(SEXP x)
{
    int n;
    SEXP val;

    if (TYPEOF(x) != REALSXP)
	error("x must be a numeric vector");

    n = LENGTH(x);
    PROTECT(val = allocVector(REALSXP, n));
    addone(REAL(x), &n, REAL(val), &n);
    UNPROTECT(1);
    return val;
}