LogString conversion

On May 9, 2008, at 7:46 AM, Mehta, Jenica wrote:

> Hi All,
>
> Please let me know if log4cxx 0.10.0 provides any API
for converting  
> std::string to log4cxx::LogString and vice versa.
>
> Thanks & Regards,
>
> Jenica Mehta
>
>

LogString is the internal string representation within
log4cxx which  
is either an std::basic_string<char> where the
characters are UTF-8  
codes (default build on non-Windows platforms) or  
std::basic_string<wchar_t> (default on Windows).  Most
of the commonly  
used methods are written accept many flavors of strings
(std::string  
in current code page, wstrings, CFString, etc), but less
frequently  
used methods require that the user explicitly between their
desired  
string type and LogString.

The simplest way to convert, is the use the
LOGCXX_ENCODE_CHAR and  
LOG4CXX_DECODE_CHAR macros defined in
log4cxx/helpers/transcoder.h.   
ENCODE creates a std::string from a LogString and DECODE
creates a  
LogString from a char.  If log4cxx is build with
--with-charset=utf-8  
and --with-logchar=utf-8, the macros will simply be a
reference  
definition since there is no need for conversion.  Here is
an example  
(don't actually run it for obvious reasons):

void bar(LogString& param) {
    LOG4CXX_ENCODE_CHAR(string, param);
    foo(string);
}

void foo(std::string& param) {
     LOG4CXX_DECODE_CHAR(logstring, param);
     bar(logstring);
}