void
test()
    PREINIT:
        SV *scalar;
    CODE:
        if ( scalar == NULL ) // fixed
            std::cout << "NULL\n"
        if ( SvOK( scalar ) ) // fixed
            std::cout << "OK\n"

##</code><code>##

void
test( ... )
    PREINIT:
        std::map< std::string, SV *> args;
    INIT:
        for ( int i = 1; i < items; i += 2 )
            args[ SvP_nolen( ST(i) ) ]
                = ST( i + 1 );
    CODE:
        std::cout << "The value of `foo' is "
                  << SvP_nolen( args["foo"] )
                  << "\n";