[Boost-users] boost.Iostream OpenSSL Filter

I am currently looking at using OpenSSL to write information to an encrypted file on-the-fly so to speak. I have been researching my options for doing this, and have come across the Boost.Iostream library, which promises to be a very elegant solution (The documentation even suggests that filters can be written to provide encryption/decryption using OpenSSL). It would seem that my best approach would be to use the BIO_f* interface to encrypt a memory buffer, which could be written by overloading write(). However the OpenSSL documentation is particularly sparse when it comes to file/memory encryption and I would appreciate any advice on how to do this. Thank you in advance for any help proffered.