On Sun, Mar 3, 2013 at 12:30 AM, Artyom Beilis <artyomtnk@yahoo.com> wrote:
________________________________ From: Andrey Semashev <andrey.semashev@gmail.com> To: boost@lists.boost.org Sent: Saturday, March 2, 2013 12:56 PM Subject: [boost] [locale] Composing asymmetric locale for character encoding conversion
Hi,
Suppose I have a logging application that writes log records in wide (wchar_t, UTF-16) and narrow (char, UTF-8) encodings and I want these logs to be stored in a UTF-16LE encoded file. For simplicity, let's assume that I write log files with std::wofstream. Now, the standard says that the file stream buffer is supposed to convert wide characters to byte sequences using the locale imbued into the buffer.
In generally it is done by codecvt facet, but it id designed to covert wide characters to 8 bit encode and vise versa.
However, it seems that the locale should be the same as the one imbued into the stream (basic_ostream::imbue makes sure of that).
No you can install your own codecvt to existing locale object and than imbue it into the stream.
I'm not sure you understood. I was pointing out there are two locales in the stream: the one in the stream and the one in the stream buffer. And apparently, they should be the same.
What this leads to is that in order to achieve my goal the locale should be able to convert narrow characters of UTF-8 to wide characters of UTF-16 and wide characters of UTF-16 to narrow characters representing byte sequence of UTF16LE. Is it possible to make such an asymmetric locale with Boost.Locale? Or maybe there is another way of doing this?
No, the stuff you are probably looking for is in an interface that provides both `std::basic_ostream<char>` and `std::basic_ostream<wchar_t>~
Hmm, why two streams? This will add operator<< ambiguity, won't it? I can already output narrow strings to wide streams, which results in character conversion (to UTF-16 wchar_t). The problem left is to convert it to UTF-16LE byte sequence. I tried to create a locale that would perform this conversion (I tried boost::locale::generator()("en_US.UTF-16LE");) and it didn't work. Does Boost.Locale support this kind of conversion?