use Inline C => <<'END_C';

SV *
get_smiley() {
    SV *const smiley_sv = newSV(3);
    SvPOK_on(smiley_sv);
    SvUTF8_on(smiley_sv);
    unsigned char *ptr = (unsigned char*)SvPVX(smiley_sv);
    *ptr++ = 0xE2;
    *ptr++ = 0x98;
    *ptr++ = 0xBA;
    *ptr   = 0x00;
    SvCUR_set(smiley_sv, 3);
    
    return smiley_sv;
}
END_C

my $smiley = get_smiley();