int 
MyLib::strToInt(passfailSV)
    SV* passfailSV
PREINIT:
    bool passfail;
CODE:
    foo(&passfail);
    SvSetMagicSV(passfailSV, passfail ? &PL_sv_yes : &PL_sv_no);
OUTPUT:
    RETVAL

##</code><code>##

T_BOOL
	$arg = boolSV($var);

##</code><code>##

/*
=for apidoc Am|SV *|boolSV|bool b

Returns a true SV if C<b> is a true value, or a false SV if C<b> is 0.

See also C<PL_sv_yes> and C<PL_sv_no>.

=cut
*/

#define boolSV(b) ((b) ? &PL_sv_yes : &PL_sv_no)