Hey, I'm new to boost and need a seekable input filter that will operate on bytes read from an ifstream. This is what I currently have:
struct my_filter : boost::iostreams::seekable_filter
{
template<typename Source>
int get(Source& src)
{
int byte = boost::iostreams::get(src);
if(byte != EOF && byte != boost::iostreams::WOULD_BLOCK)
{
// Do something with byte
}
return byte;
}
template<typename Sink>
bool put(Sink&, char)
{
// No need to actually implement put because this filter is only used with ifstream
return true;
}
template<typename T>
std::streampos seek(T& t, boost::iostreams::stream_offset off, std::ios_base::seekdir way, std::ios_base::openmode which = std::ios_base::in | std::ios_base::out)
{
return boost::iostreams::seek(t, off, way, which);
}
};
It works but I would like to get rid of the useless put method. The boost documentation herehttp://www.boost.org/doc/libs/1_60_0/libs/iostreams/doc/concepts/filter.html says there is an InputSeekableFilter refinement of Filter but I can't seem to understand how to use it (there are no input_seekable_filter_tag or input_seekable_filter structs that I could use).
Thanks