On Thu, 16 Nov 2017 12:29:37 +0100 Paolo Carlini <paolo.carl...@oracle.com> wrote:
> Hi, > > On 16/11/2017 12:03, Petr Ovtchenkov wrote: > > On Thu, 16 Nov 2017 10:39:02 +0100 > > Paolo Carlini <paolo.carl...@oracle.com> wrote: > > > >> Hi, > >> > >> On 16/11/2017 06:31, Petr Ovtchenkov wrote: > >>> Is we really worry about frozen sizeof of instantiated template? > >> Yes we do. See https://gcc.gnu.org/onlinedocs/libstdc++/manual/abi.html > >> under "Prohibited Changes", point 8. > >> > >> Of course removing the buffering has performance implications too - > >> that's why it's there in the first place! > > "buffering" here is a secondary buffering (after streambuf). > > No relation to performance, but place for incoherence with > > state of attached streambuf. > It depends, we may be dealing with an unbuffered stream. For sure at the > time we measured a performance impact in some cases, likewise whoever > implemented it in the first place (not me) otherwise, again, why bothering? This part of code is from SGI, so I suspect that nobody here really measure performance difference between "bufferred" and "non-buffered" implementations. Just because we have only implementation with _M_c in isreambuf_iterator. > > Paolo. > -- - ptr
