PackedBits

[lch2]

I have a incoming packet of 75 bytes. It is packed of five 10 Bitters and five 5 Bitters. like 10-5-10-5-... What is the best way to receive-parse-modify and send the packet back using struct/union or any ther way.

[Alex F]

Use bit fields: http://msdn.microsoft.com/en-us/libr...=vs.71%29.aspx

[VladimirF]

I have a incoming packet of 75 bytes. It is packed of five 10 Bitters and five 5 Bitters. like 10-5-10-5-... What is the best way to receive-parse-modify and send the packet back using struct/union or any ther way.

What is a "10 Bitter"? 10-bit value? Packed into what?
Trying to figure out your math. If you have five 10-bit values and five 5-bit - this only makes 75 BITS, not bytes. What am I doing wrong?

[ninja9578]

Pretty sure you will also need the extern "C" for this, because C++ will pad however it wishes.

[mlgoff]

No, he won't need to extern it. C++ will not pad it if he builds his struct properly.

struct SomeBits
{
    unsigned short first_10_bits : 10;
    unsigned char next_5_bits : 5;
    unsigned short next_10_bits : 10;
    unsigned char next_5_bits : 5;
    unsigned short next_10_bits : 10;
    unsigned char next_5_bits : 5;
    unsigned short next_10_bits : 10;
    unsigned char next_5_bits : 5;
    unsigned short next_10_bits : 10;
    unsigned char next_5_bits : 5;
    unsigned char pad :5;

Always try to allign your packed structs on word boundries, at the very least.