Re: Regex and Unicode

From: Frédéric Mayot (yg-boost-users_at_[hidden])
Date: 2002-09-18 08:31:23

John Maddock wrote:
>> I'm trying to use Unicode with Regex in an MFC app. The preprocessor
>> variable UNICODE is defined. But I obtain an error on the line :
>>
>> regex_search(sText, oResults, pRegExp);
>> error C2665: none of the 4 overloads can convert parameter 1 from
>> type 'class CString'
>>
>> sText is a CString which has a "const wchar_t*" operator. The
>> problem is why doesn't the regex_search prototype require a "const
>> wchar_t*" when UNICODE is defined ?
>
> You did, use sText.c_str() to get a const wchat_t*, otherwise there
> are too many overloaded forms of the function for the conversion to
> be found automatically.

I tried the "const wchar_t*" operator :
regex_search((const wchar_t*) sText, oResults, pRegExp);
but the problem is not here.
VC++6 wrote :
error C2664: '__thiscall boost::reg_expression<char,class
boost::regex_traits<char>,class boost::detail::allocator_adapter<char,class
boost::detail::simple_alloc> >::boost::reg_expression<char,class
boost::regex_traits<char>,class boost::detail::allocator_adapter<char,class
boost::detail::simple_alloc> >(const class
boost::detail::allocator_adapter<char,class boost::detail::simple_alloc> &)'
: cannot convert parameter 1 from 'const unsigned short *' to 'const class
boost::detail::allocator_adapter<char,class boost::detail::simple_alloc> &'
        Reason: cannot convert from 'const unsigned short *' to 'const class
boost::detail::allocator_adapter<char,class boost::detail::simple_alloc>'
        No constructor could take the source type, or constructor overload
resolution was ambiguous

You see that the reg_expression prototype contains "char"s and not
"wchar_t"s.
Are you sure that the only thing to do to use UNICODE is to put a #define
UNICODE (I put it in my stdafx.h and in my project settings)?

Thanks.

Fred