Large file iostreams

[Nathan Myers]

On Thu, Sep 04, 2003 at 06:23:46PM -0600, Martin Sebor wrote:
> 
> ... our own
> implementation uses mbstate_t values that have nothing to do
> with those used by the C library (we still use mbstate_t() to
> denote the initial shift state).
> 
> I think that the intent (Nathan could clarify this) must have
> been that C++ codecvt be (possible to be) implemented in terms
> of the C multibyte functions. Otherwise I don't see why even
> specify mbstate_t in C++ locale and not some completely
> unrelated state type.

On the contrary.  It was specifically intended that better
implementations would _not_ use the C multibyte functions.  (Indeed,
I personally expected that the better implementations would have their 
own versions of the C functions built on top of the C++ library 
features.  That seems still to come.)  

Since it was clear that some implementations would need to use the 
C functions, we chose to use mbstate_t to hold the state to make 
that choice easier to implement.  In retrospect it was probably a 
mistake not to have abstracted it, as it has made it harder to make 
a C++ library portable across C libraries.

Nathan Myers
ncm-nospam@cantrip.org