//Purpose:
//  test if there exists filtering_stream<Mode>::sync function.
//
#include <boost/iostreams/filtering_stream.hpp>
template<typename Mode>
bool test()
{
    bool dummy=false;
        typedef 
      boost::iostreams::filtering_stream
      < Mode
      >
    out;
    auto mptr_strict=&out::strict_sync;
    dummy|=bool(mptr_strict);
  #if 1
    auto mptr_sync=&out::sync;
    dummy|=bool(mptr_sync);
  #endif
    return dummy;
}
int main()
{
    test<boost::iostreams::input>();
    test<boost::iostreams::output>();
    return 0;
}
//Result:
/*
/home/evansl/dwnlds/gcc/4.8-20121028/install/bin/g++ -c  -O0 -gdwarf-2 -Wall -Wstrict-overflow -ftemplate-depth-300  -Wno-unused-local-typedefs -Wno-unused-but-set-variable  -std=gnu++11 -I/home/evansl/prog_dev/boost/boost-svn/ro/boost_1_54_0/sandbox/rw/non_variadic_templates -I/home/evansl/prog_dev/boost/boost-svn/ro/boost_1_54_0    -DTEMPLATE_DEPTH=300  filtering_stream.sync.cpp -MMD -o filtering_stream.sync.o 
filtering_stream.sync.cpp: In function 'int main()':
filtering_stream.sync.cpp:12:21: error: 'sync' is not a member of 'out {aka boost::iostreams::filtering_stream<boost::iostreams::output>}'
     auto mptr_sync=&out::sync;
                     ^
make: *** [filtering_stream.sync.o] Error 1
 */