SymmetricFilter does not compile with non-char types

[anonymous]

If I use SymmetricFilter template with a type other than char (i.e. uint8_t) I get a compiler error when compiling boost/iostreams/filter/symmetric.hpp:

template<typename Sink> void close(Sink& snk, BOOST_IOS::openmode which)

IMHO the lines

char dummy; const char* end = &dummy;

should read

char_type dummy; const char_type* end = &dummy;

Please consider a change.

[Steven Watanabe]

(In [63006]) Make symmetric_filter compile with wchar_t. Fixes #3279.