Re: [boost] IOstreams: Why are mapped_file devices not seekable?

Schalk Cronje wrote:

In both of the implementations of mapped_file_source and mapped_file_sink, the devices are not seekable (whereas basic_array_source and basic_array_sink are).

I am wondering whether there is a rationale for this, or whether it was simply an oversight in development. Since mapped_files are still contiguous piece of memory I see no reason why they should not be seekable.

No. Because the DirectDevice doesn't have a stream position. The DirectDevice is not strictly a Device. If you use the class direct_adapter, you can get a Seekable. See also: #include <boost/iostreams/detail/adapter/direct_adapter.hpp> Regards, Takeshi Mouri