Some basic questions about Boost filtering_streams. I have dozens of functions that presently take a parameter of std::ofstream&. For example:
void foo(std::ofstream& outStream)
{
// lots of operations, like this:
outStream << "various bits of text";
}
Which then get used as thus:
void StreamSomeTextToFile(char* fileName)
{
ofstream myFileStream(fileName, ios::out | ios::app | ios::binary);
foo(myFileStream);
myFileStream.close();
}
Now I'd like to use the boost filtering_stream to output to a compressed ZIP file. I've compiled, linked and run the commonly cited boost filtering_stream test code for packing and unpacking and it worked perfectly for me. Now I'd like to try to substitute my use of std::ofstream& with the filtering_stream:
void StreamSomeCompressedTextToFile(char* fileName)
{
ofstream myFileStream(destPath, std::ios_base::out | std::ios_base::app | std::ios_base::binary);
boost::iostreams::filtering_streambufboost::iostreams::output myCompressedFileStream;
myCompressedFileStream.push(boost::iostreams::zlib_compressor());
myCompressedFileStream.push(myFileStream);
foo(myCompressedFileStream); // I can't just pass myCompressedFileStream to foo(std::ofstream&), right?
myFileStream.close();
}
THREE QUESTIONS:
1) Do all my functions that previously accepted std::ofstream& outStream need to now accept a parameter of type boost::iostreams::filtering_streambufboost::iostreams::output& ? Or, is there a proper parameter type so those numerous ("foo") functions could work with EITHER type of stream type?
2) In my simple test cases, I was not able to use stream operator syntax with the filtering_streambuf:
myCompressedFileStream << "some text";
this generated the the error: no match for 'operator<<'. I similarly had compile errors with write():
`error: 'class boost::iostreams::filtering_streambuf