[PATCH 3/4] libstdc++: avoid character accumulation in istreambuf_iterator

[Paolo Carlini]

Hi,

On 15/11/2017 11:48, Petr Ovtchenkov wrote:
> Ask associated streambuf for character when needed instead of
> accumulate it in istreambuf_iterator object.
>
> Benefits from this:
>    - minus one class member in istreambuf_iterator
>    - trivial synchronization of states of istreambuf_iterator
>      and associated streambuf
> ---
>   libstdc++-v3/include/bits/streambuf_iterator.h | 34 ++++++++++++--------------
>   1 file changed, 15 insertions(+), 19 deletions(-)
>
> diff --git a/libstdc++-v3/include/bits/streambuf_iterator.h b/libstdc++-v3/include/bits/streambuf_iterator.h
> index 08fb13b..203da9d 100644
> --- a/libstdc++-v3/include/bits/streambuf_iterator.h
> +++ b/libstdc++-v3/include/bits/streambuf_iterator.h
> @@ -95,19 +95,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>         // NB: This implementation assumes the "end of stream" value
>         // is EOF, or -1.
>         mutable streambuf_type*	_M_sbuf;
> -      mutable int_type		_M_c;
Obviously this would be an ABI-breaking change, which certainly we don't 
want. Unless I missed a detailed discussion of the non-trivial way to 
avoid it in one of the recent threads about these topics...

Paolo.