Re: [boost] [iochain] mutable_buffer issues

From: Robert Dailey (rcdailey_at_[hidden])
Date: 2008-07-17 15:04:40

On Thu, Jul 17, 2008 at 1:20 PM, Robert Dailey <rcdailey_at_[hidden]> wrote:
> Assume the following code, which I wrote in an attempt to test very
> basic functionality of Boost.Iostream:
>
> namespace io = boost::io;
>
> void foo()
> {
>        std::vector<boost::uint8_t> data;
>        io::source<io::iobyte> src(     io::chain( io::read_mem( data ) ) );
>
>        io::iobyte rcvbuffer;
>        const io::mutable_buffer<io::iobyte> mutbuffer( &rcvbuffer, sizeof(
> rcvbuffer ) );
>        src.read( mutbuffer );
> }
>
> The first issue I have is with mutable_buffer. Notice how it requires
> a template argument that *must* be the exact type passed into the
> io::source template parameter, in this case io::iobyte. Passing any
> other type in here results in lots of compiler errors on MSVC 9.
> Basically my biggest issue with this is that I can't pass an "int"
> into the mutable_buffer here if I want to read 4 bytes, because the
> type passed in must match io::iobyte. In my opinion, mutable_buffer
> should accept *any* type and just read in the number of bytes
> requested. Without this I fail to see the usefulness of
> mutable_buffer.
>
> The second issue has to do with the type of the first parameter in
> io::source::read(). Notice it takes a "const mutable_buffer&". Why is
> it taking a const mutable_buffer if the buffer is mutable? This seems
> conceptually wrong. I would expect it to take a "mutable_buffer&".
>

Correction:

Above I said Boost.Iostream, I meant to say Boost.Iochain. Apologies
for the confusion.