id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
5769	"fstream.hpp facilities not usable for paths containing characters outside of the current Windows (""ANSI"") code page on GCC (mingw/mingw-w64)"	sam@…	Beman Dawes	"GCC's libstdc++ does not follow MS VC++'s lead in extending std::fstream and std::filebuf to take paths made up of wchar_t strings.

boost::filesystem::filebuf and {i,o,}fstream rely on this functionality. In its absence, they fall back to converting the path's wchar_t representation into a char string in the Windows (""ANSI"") code page of the current system locale (actually, they incorrectly use the current thread codepage, see #5592).

The fstream facilities are therefore unusable with GCC when you build a Windows program that manipulates paths containing characters that are not representable in the current Windows code page.

When compiled with the GCC from mingw-w64, the attached test will fail to create a file. Examination with Process Monitor reveals that the program tries to create a file with the name of ""umbre??a"", because the ☂ character is not representable in any Windows code page.

GCC provides a __gnu_cxx::stdio_filebuf, which may be constructed from a FILE* or file descriptor; this could be used in concert with MSVCRT's _wfopen or _wopen functions, by boost::filesystem::{i,o,}fstream to provide the missing functionality."	Bugs	new	To Be Determined	filesystem	Boost 1.46.1	Problem