#! perl -slw
use strict;
use Inline C => Config => BUILD_NOISY => 1,;
use Inline C => <<'END_C',  NAME => 'bitfields', CLEAN_AFTER_BUILD =>0;

#include "mytypes.h"

union {
    struct {
        unsigned b00:1; unsigned b01:1; unsigned b02:1; unsigned b03:1;
        unsigned b04:1; unsigned b05:1; unsigned b06:1; unsigned b07:1;
        unsigned b08:1; unsigned b09:1; unsigned b10:1; unsigned b11:1;
        unsigned b12:1; unsigned b13:1; unsigned b14:1; unsigned b15:1;
        unsigned b16:1; unsigned b17:1; unsigned b18:1; unsigned b19:1;
        unsigned b20:1; unsigned b21:1; unsigned b22:1; unsigned b23:1;
        unsigned b24:1; unsigned b25:1; unsigned b26:1; unsigned b27:1;
        unsigned b28:1; unsigned b29:1; unsigned b30:1; unsigned b31:1;
    } bits;
    U32 uint;
} X;

U32 test( SV *unused ) {
    X.uint = 0x01234567;

    printf( "%u\n", X.uint );
    printf( "%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c\n",
      X.bits.b00 ? '1' : '0', X.bits.b01 ? '1' : '0', X.bits.b02 ? '1' : '0',
      X.bits.b03 ? '1' : '0', X.bits.b04 ? '1' : '0', X.bits.b05 ? '1' : '0',
      X.bits.b06 ? '1' : '0', X.bits.b07 ? '1' : '0', X.bits.b08 ? '1' : '0',
      X.bits.b09 ? '1' : '0', X.bits.b10 ? '1' : '0', X.bits.b11 ? '1' : '0',
      X.bits.b12 ? '1' : '0', X.bits.b13 ? '1' : '0', X.bits.b14 ? '1' : '0',
      X.bits.b15 ? '1' : '0', X.bits.b16 ? '1' : '0', X.bits.b17 ? '1' : '0',
      X.bits.b18 ? '1' : '0', X.bits.b19 ? '1' : '0', X.bits.b20 ? '1' : '0',
      X.bits.b21 ? '1' : '0', X.bits.b22 ? '1' : '0', X.bits.b23 ? '1' : '0',
      X.bits.b24 ? '1' : '0', X.bits.b25 ? '1' : '0', X.bits.b26 ? '1' : '0',
      X.bits.b27 ? '1' : '0', X.bits.b28 ? '1' : '0', X.bits.b29 ? '1' : '0',
      X.bits.b30 ? '1' : '0', X.bits.b31 ? '1' : '0'
    );
    return X.uint;
}

END_C

my $uint = test( 1 );
print unpack 'b*', pack 'V', $uint;
print unpack 'B*', pack 'V', $uint;

__END__
C:\test>bitFields.pl
19088743
11100110101000101100010010000000
11100110101000101100010010000000
01100111010001010010001100000001