Stefan Slapeta wrote:
Robert Ramey wrote:
Note that the implementation above is not dependent on codecvt nor on streams.
This is absolutely crucial. Imagine you have to read XML files with many thousands of strings...
BTW, that's the same reason that lexical_cast isn't applicable for many real cases. Its catastrophic performance inhibits every usage whenever speed _could_ be an issue...
Streams aren't as slow as you think. For converting large amounts of data, a stream-based approach can quite fast. The most expensive aspect of using streams are: - initialization, if you have to create a new stream each time you want to convert or format a small amount of data - the formatted i/o operations The code_converter component doesn't incur either cost. A code_converter can be constructed once and used many times. It can also convert between narrow and wide characters without invoking any formatted i/o operations.
I would like to see this conversion functions available at a more general place than the serialization library. But probably there is much more to do to improve internationalization support than only providing string/wstring conversion ;)
The code_converter component from the iostreams library is already quite flexible. It might make sense to have a specialized component for converting strings, but I'd like it to be general enough to handle any type of string. Robert's approach, using iterator adaptors, might be a good way to go. But a Codecvt should be a template parameter: template< typename Codecvt, typename Iterator ... > class converting_iterator;
Stefan
Jonathan