[boost] Re:Unable to build line_wrapping_output_filter with _UNICODE defined (was: IOStreams formal review start)

From: George M. Garner Jr. (gmgarner_at_[hidden])
Date: 2004-09-09 14:51:48

Jonathan,

I am trying to build some of your samples with _UNICODE;UNICODE defined 
using Visual Studio 2003 and get a build error which is included in detail 
at the end of this message.
Since you do not provide a Unicode sample I have modified your sample to 
support the Windows _TCHAR macros.  The modified source code also is 
included at the end of this message.  The code compiles and runs when 
_UNICODE is not defined.  The build error occurs only with the Unicode 
build.

Regards,

George.

Compiling...
line_wrapping_example.cpp
h:\source code\Turkanis\iostream\boost\io\detail\chain.hpp(169) : error 
C2664: 'std::list<_Ty>::push_back' : cannot convert parameter 1 from 
'facade_type *' to 'boost::io::detail::linked_streambuf<Ch> & '
with
[
_Ty=boost::io::detail::chain_base<boost::io::detail::chain<boost::io::output,wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>,boost::io::output>::streambuf_type 
*
]
and
[
Ch=wchar_t
]
Reason: cannot convert from 'facade_type *' to 
'boost::io::detail::linked_streambuf<Ch> '
with
[
Ch=wchar_t
]
Types pointed to are unrelated; conversion requires reinterpret_cast, 
C-style cast or function-style cast
h:\source code\Turkanis\iostream\boost\io\detail\chain.hpp(134) : see 
reference to function template instantiation 'void 
boost::io::detail::chain_base<Self,Ch,Tr,Alloc,Mode>::push_impl<T>(const T 
&,std::streamsize,std::streamsize)' being compiled
with
[
Self=boost::io::detail::chain<boost::io::output,wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,
Ch=wchar_t,
Tr=std::char_traits<wchar_t>,
Alloc=std::allocator<wchar_t>,
Mode=boost::io::output,
T=boost::io::example::line_wrapping_output_filter
]
h:\source code\Turkanis\iostream\boost\io\detail\chain.hpp(317) : see 
reference to function template instantiation 'void 
boost::io::detail::chain_base<Self,Ch,Tr,Alloc,Mode>::push<T>(const T 
&,std::streamsize,std::streamsize,boost::disable_if_c<B,void>::type *)' 
being compiled
with
[
Self=boost::io::detail::chain<boost::io::output,wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,
Ch=wchar_t,
Tr=std::char_traits<wchar_t>,
Alloc=std::allocator<wchar_t>,
Mode=boost::io::output,
T=boost::io::example::line_wrapping_output_filter,
B=false
]
h:\source code\Turkanis\iostream\boost\io\detail\chain.hpp(310) : see 
reference to function template instantiation 'void 
boost::io::detail::chain_client<Chain>::push_impl<T>(const T 
&,std::streamsize,std::streamsize)' being compiled
with
[
Chain=boost::io::detail::chain<boost::io::output,wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,
T=boost::io::example::line_wrapping_output_filter
]
h:\Projects\Turkanis\example\line_wrapping_example\line_wrapping_example.cpp(46) 
: see reference to function template instantiation 'void 
boost::io::detail::chain_client<Chain>::push<boost::io::example::line_wrapping_output_filter>(const 
T &,std::streamsize,std::streamsize,boost::disable_if_c<B,void>::type *)' 
being compiled
with
[
Chain=boost::io::detail::chain<boost::io::output,wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,
T=boost::io::example::line_wrapping_output_filter,
B=false
]

//line_wrapping_output_filter.hpp
#ifndef BOOST_IO_EXAMPLE_LINE_WRAPPING_OUTPUT_FILTER_HPP_INCLUDED
#define BOOST_IO_EXAMPLE_LINE_WRAPPING_OUTPUT_FILTER_HPP_INCLUDED
#include <boost/io/concepts.hpp> // output_filter.
#include <boost/io/operations.hpp> // boost::io::put.
namespace boost { namespace io { namespace example {
class line_wrapping_output_filter : public output_filter {
public:
explicit line_wrapping_output_filter(int line_length = 80)
: line_length_(line_length), col_no_(0) { }
template<typename Sink>
void put(Sink& dest, int c)
{
if (c == __T('\n'))
col_no_ = 0 ;
else {
if (col_no_ >= line_length_)
this->put(dest, __T('\n'));
++col_no_ ;
}
boost::io::put(dest, c);
}
template<typename Sink>
void close(Sink& dest) { boost::io::put(dest, __T('\n')); col_no_ = 0; }
private:
int line_length_ ;
int col_no_;
};
} } } // End namespaces example, io, boost.
#endif // #ifndef BOOST_IO_EXAMPLE_LINE_WRAPPING_OUTPUT_FILTER_HPP_INCLUDED
//line_wrapping_filter.cpp
#include <windows.h>
#include <tchar.h>
#include <iostream>
#include <boost/io/filtering_stream.hpp>
#include "line_wrapping_output_filter.hpp"

#ifdef _UNICODE
#define filtering_tostream filtering_wostream
#define _tcout wcout
#else
#define filtering_tostream filtering_ostream
#define _tcout cout
#endif //_UNICODE
//
// Demonstrates the use of line_wrapping_output_filter.
//
void test_line_wrapping()
{
using namespace std;
using namespace boost::io;
using namespace boost::io::example;
const _TCHAR* text =
__T("In the country of Westphalia, in the castle of the most noble Baron ")
__T("of Thunder-ten-tronckh, lived a youth whom Nature had endowed with a ")
__T("most sweet disposition. His face was the true index of his mind. He ")
__T("had a solid judgment joined to the most unaffected simplicity; and ")
__T("hence, I presume, he had his name of Candide. The old servants of the 
")
__T("house suspected him to have been the son of the Baron's sister, by a ")
__T("very good sort of a gentleman of the neighborhood, whom that young ")
__T("lady refused to marry, because he could produce no more than ")
__T("threescore and eleven quarterings in his arms; the rest of the ")
__T("genealogical tree belonging to the family having been lost through ")
__T("the injuries of time....\n");
filtering_tostream out;
out.push(line_wrapping_output_filter(50));
out.push(_tcout);
// Print unfiltered text.
_tcout << __T("**** Candide ****\n\n") << text << __T("\n\n");
// Print filtered text:
out << __T("**** Candide with line wrapping ****\n\n") << text << 
__T("\n\n");
}
int _tmain()
{
test_line_wrapping();
return 0;
}