writing/adding 1 bit into stream

[METALRAGE]

I have a file which I'm trying to write to. I opened it with an object of fstream class in binary mode and out mode (ios::binary | ios:ut).

Now, I have no problems reading/writing characters to the file. I also have no problems reading/writing a structure to the file.

struct record
{
   int i;
   char *name;
}student;

void write()
{
   fstream newFile;

   //yada yada bla bla... (Insert rest of codes here)   

   newFile.write(reinterpret_cast<const char *>(&student);
   newFile.write("Male");
}

This code is output in binary format, thus, when you open the text file with notepad, some of it is intelligible.

The problem is, now I want to write a binary file, inputting the binary streams in variable sized length of bits.

Eg. I want to output "1010 100 001111 011 01 1100" to the file, as binary code, not characters.

is there any way I can do this?

1) I've tried using bool datatype with true/false. but when I write the boolean variable into the file, it still outputs them in 8 bit chunks.
I checked in the debugger and boolean datatypes take up 1 whole byte although there are only 2 combinations available. "0x00" AND "0x01"

2) i tried enumerating my own boolean values, but there seems to be no binary format in C++. "0b". is there any other way that i don't know about, or did i do anything wrong?

3) is there anyway to do this with bitwise manipulation? 'cos all the bitwise manipulations i know doesn't add bits to a stream, but it just change their values.

4) is there an already known and available method for writing just 1 bit to a stream?


any help would be appreciated, thank you.

[twanvl]

1. Writing a bool will write at least one whole byte.
2. ?
3. Yes it is possible to write single bits using bitwise operators, you first store your bits untill they form a whole byte, then you write that byte to the file.
4. no

But I wonder, why do you want to do this? The only uses I can think of are related to huge arrays of bits or data compression.

[METALRAGE]

wow. u know ur stuff!

data compression it is

thx for the clarifications, i'll c what i can do according to ur guidelines. but expect more newbie questions in the future

[Darkwraith]

When you are outputing to the stream, you want to package the bits into bytes and then output each byte to the stream.

I think I have some code lying around for packing bits if you want it.

[METALRAGE]

a little help from sample codes wouldn't hurt .


how do i get u?

[Darkwraith]

Its my teacher's code that he made us write first.

We had to use this in a compression project so it should work.

[Darkwraith]

The header for this.

[METALRAGE]

thanks a bunch =)