Hi I'm using NetBeans 8.0 and x64-4.8.1-win32-seh-rev5 distribution for the gcc C++11 compiler as recommended for C++11 by the good folks at NetBeans.org. My computer is a 64-bit Win 7 SP1. [Also updated msys to rev 13.] I have searched the entire distro for the C++11 wstring_convert<> class and it is not there! I also note that there is no codecvt file in the main include directory (C:\Program Files\mingw-builds\x64-4.8.1-win32-seh-rev5\mingw64\lib\gcc\x86_64-w64-mingw 32\4.8.1\include\c++). Yes, I do need this - I have to handle the filing system on Windows, but for some strange reason, std::ifstream constructor only supports filenames in char (actually as far as I can tell it's the same for wifstream too, i.e. filenames are char). This appears to be a deficiency in the C++ standard as both char (std::string) and wchar_t (std::wstring) should be able to be used to specify the filename to be used for the stream. Because of this, I have to convert the UNICODE used in Windows for filenames into ASCII - risky, this could fail with valid (for Windows) filenames. The other (related) problem is finding a way to set up main() so that the argv is wchar_t. Reason: main() in VS2010 programs needs to be int _tmain(int argc, _TCHAR* argv[]) {.}. This is so the command line UNICODE filenames can be successfully handled. Conversion of the main() interface to compile with gcc requires at least: 1. Inclusion of tchar.h (for _TCHAR and other defs) 2. Addition of a pre-processor definition _UNICODE (to select wchar_t definitions for _TCHAR and __T). 3. Something to prevent the linker error (see below) and successfully complete. [Note the WinMain ref] "/C/msys/bin/make.exe" -f nbproject/Makefile-Debug.mk QMAKE= SUBPROJECTS= .build-conf make.exe[1]: Entering directory `/e/__Working/MOSRT/MOSRT' "/C/msys/bin/make.exe" -f nbproject/Makefile-Debug.mk dist/Debug/MinGW-Windows/mosrt.exe make.exe[2]: Entering directory `/e/__Working/MOSRT/MOSRT' mkdir -p build/Debug/MinGW-Windows/_ext/1472 rm -f "build/Debug/MinGW-Windows/_ext/1472/OSRT.o.d" g++ -D_UNICODE -c -DNET_BEAN -D_UNICODE -std=c++11 -MMD -MP -MF "build/Debug/MinGW-Windows/_ext/1472/OSRT.o.d" -o build/Debug/MinGW-Windows/_ext/1472/OSRT.o ../OSRT.cpp mkdir -p dist/Debug/MinGW-Windows g++ -D_UNICODE -o dist/Debug/MinGW-Windows/mosrt build/Debug/MinGW-Windows/_ext/1472/OSRT.o build/Debug/MinGW-Windows/_ext/1472/TCodeMaker.o build/Debug/MinGW-Windows/_ext/1472/TDefs.o build/Debug/MinGW-Windows/_ext/1472/TInfo.o build/Debug/MinGW-Windows/_ext/1472/TMessage.o build/Debug/MinGW-Windows/_ext/1472/TTaskIdentity.o build/Debug/MinGW-Windows/_ext/1472/ini.o build/Debug/MinGW-Windows/_ext/1472/log.o c:/program files/mingw-builds/x64-4.8.1-win32-seh-rev5/mingw64/bin/../lib/gcc/x86_64-w6 4-mingw32/4.8.1/../../../../x86_64-w64-mingw32/lib/../lib/libmingw32.a(lib64 _libmingw32_a-crt0_c.o):crt0_c.c:(.text.startup+0x25): undefined reference to `WinMain' collect2.exe: error: ld returned 1 exit status nbproject/Makefile-Debug.mk:69: recipe for target `dist/Debug/MinGW-Windows/mosrt.exe' failed make.exe[2]: *** [dist/Debug/MinGW-Windows/mosrt.exe] Error 1 make.exe[2]: Leaving directory `/e/__Working/MOSRT/MOSRT' nbproject/Makefile-Debug.mk:66: recipe for target `.build-conf' failed make.exe[1]: *** [.build-conf] Error 2 make.exe[1]: Leaving directory `/e/__Working/MOSRT/MOSRT' nbproject/Makefile-impl.mk:39: recipe for target `.build-impl' failed make.exe": *** [.build-impl] Error 2 BUILD FAILED (exit value 2, total time: 3s) I hope you can either help or at least provide some bug tracking info so as I can follow the progress of these issues. The (cause of the) linker error is the worst for me as I need to get developing and no link is a showstopper. With kind regards Jack Sharman