/* Convert a simple string representation of a value into a more specific
 * perl type based on an sql_type value.
 * The semantics of SQL standard TYPE values are interpreted _very_ loosely
 * on the basis of "be liberal in what you accept and let's throw in some
 * extra semantics while we're here" :)
 * Returns:
 *  -2: sql_type isn't handled, value unchanged
 *  -1: sv is undef, value unchanged
 *   0: sv couldn't be cast cleanly and DBIstcf_STRICT was used
 *   1: sv couldn't be cast cleanly and DBIstcf_STRICT was not used
 *   2: sv was cast ok
 */

int
sql_type_cast_svpv(pTHX_ SV *sv, int sql_type, U32 flags, void *v)
{
    int cast_ok = 0;

    switch(sql_type) {

    default:
        return -2;   /* not a recognised SQL TYPE, value unchanged */
 
    case SQL_DOUBLE:    {
        /* mje - I don't understand why sv_2nv returns 0 in the following when sv is "aa" */ 
        sv_2nv(sv);
        /* SvNOK should be set but won't if sv is not numeric (in which
         * case perl would have warn'd already if -w or warnings are in effect)
         */
        /* mje it is true perl warns if sv is "aa" and warnings enabled so it knew it was not a number
           so why is cast_ok = 512 */
        cast_ok = SvNOK(sv);
        break;
    }
    }

    if (cast_ok)
        return 2; /* mje always getting here but wanted 0 or 1 depending on DBIstcf_STRICT */
    else if (flags & DBIstcf_STRICT)
        return 0;
    else return 1;
}