Can't write string of 1 and 0 to binary file, C++

Question

I have the function that receives a pointer to a string with a name of file to open and to code with 1 and 0; codedLine contains something like 01010011010

Answer 1

After writing to binary file I have exactly the same...

I suppose you want to convert the std::string input to its binary equivalent.

You can use the std::bitset<> class to convert strings to binary values and vice versa. Writing the string directly to the file results in binary representations of the character values '0' and '1'.

An example how to use it:

std::string zeroes_and_ones = "1011100001111010010";
// Define a bitset that can hold sizeof(unsigned long) bits
std::bitset bits(zeroes_and_ones);

unsigned long binary_value = bits.to_ulong();

// write the binary value to file
codedFile.write((const char*)&binary_value, sizeof(unsigned long));

NOTE
The above sample works with c++11 standards. For earlier version the std::bitset can't be initialized directly from the string. But it can be filled using the operator>>() and std::istringstream for example.