Boost C++ Libraries: Ticket #791: iostreams::tee_filter is for output only

alexis_wilke — Mon, 11 Dec 2006 08:31:55 GMT

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I propose the following additional function and adding multichar_input_filter_tag to the category. My software seems to work just fine with this addition.
    template<typename Source>
    std::streamsize read(Source& src, char_type* s, std::streamsize n)
    {
        int   c;
        char_type* first = s;
        char_type* last  = s + n;
        while ( first != last &&
                (c = boost::iostreams::get(src)) != EOF &&
                 c != WOULD_BLOCK )
        {
            *first++ = c;
        }
        std::streamsize result = static_cast<std::streamsize>(first - s);
        if(result == 0)
        {
           return c;
        }
        std::streamsize result2 = iostreams::write(this->component(), s, result);
        (void) result2; // Suppress 'unused variable' warning.
        assert(result == result2);
        return result;
    }

component changed; severity set

Daryle Walker — Fri, 03 Aug 2007 12:18:00 GMT

component None → iostreams
severity → Problem

type changed; milestone set

Jonathan Turkanis — Sun, 30 Dec 2007 08:44:17 GMT

type Bugs → Feature Requests
milestone → Boost 1.36.0

When I wrote tee, I couldn't think of a way to apply the concept to an input stream, but your idea looks pretty good. I will consider it for 1.36.

status, resolution changed

Jonathan Turkanis — Sun, 25 May 2008 22:03:23 GMT

status assigned → closed
resolution None → fixed

(In [45752]) made tee work with input streams (fixes #791)