[Boost-users] Possible bug in iostreams: multichar_wfilter vs multichar_filter

From: Chad Walters (chad_at_[hidden])
Date: 2007-05-22 14:51:51

I was looking through the iostreams sources and came across this in
boost/iostreams/concepts.hpp:

//------Definitions of helper templates for multi-character filter
cncepts----//

template<typename Mode, typename Ch = char>
struct multichar_filter : filter<Mode, Ch> {
    struct category : filter<Mode, Ch>::category, multichar_tag { };
};

template<typename Mode, typename Ch = wchar_t>
struct multichar_wfilter : multichar_filter<Mode, Ch> { };

typedef multichar_filter<input>     multichar_input_filter;
typedef multichar_filter<input>     multichar_input_wfilter;
typedef multichar_filter<output>    multichar_output_filter;
typedef multichar_filter<output>    multichar_output_wfilter;
typedef multichar_filter<dual_use>  multichar_dual_use_filter;
typedef multichar_filter<dual_use>  multichar_dual_use_wfilter;

//--------------------------------------------------------------------------
--//

It seems to me that the wide versions of these typedefs should be defined
using multichar_wfilter, making the typedefs appear as follows:

typedef multichar_filter<input>     multichar_input_filter;
typedef multichar_wfilter<input>    multichar_input_wfilter;
typedef multichar_filter<output>    multichar_output_filter;
typedef multichar_wfilter<output>   multichar_output_wfilter;
typedef multichar_filter<dual_use>  multichar_dual_use_filter;
typedef multichar_wfilter<dual_use> multichar_dual_use_wfilter;

Also, the default arguments in multichar_filter and multichar_wfilter
termplates aren't wrapped in BOOST_IOSTREAMS_DEFAULT_ARG(), unlike the other
ones in this file. Seems like they should be, for consistency if nothing
else.

Chad