Hello. I'm not sure, if this code should to compile in accordance with ISO, but it compiles by g++ 4.1.1 and by VC2003-2005. Here is a little test for it: --------------------------------------------------------- template<class T> class Base { protected: T x; Base() {} }; template <class T,int num> class Der: public Base<T> { public: using Base<T>::x; Der():Base<T>() {} int get(); }; template <class T> class Der<T,4>: public Base<T> { public: using Base<T>::x; //!! Der():Base<T>() {} int get(); }; template <class T,int num> int Der<T,num>::get() { return x-num; } template <class T> int Der<T,4>::get() { return x+4; //38 row. The error is here. x is not declared in this scope. } int main() { return 0; } --------------------------------------------------------- Compilation output: --------------------------------------------------------- C:\prg\test\mingw_templ>g++ main.cpp main.cpp: In member function `int Der<T, 4>::get()': main.cpp:38: error: `x' was not declared in this scope --------------------------------------------------------- Compiler version information: --------------------------------------------------------- C:\prg\test\mingw_templ>g++ -v Reading specs from C:/Install/MinGW/bin/../lib/gcc/mingw32/3.4.5/specs Configured with: ../gcc-3.4.5/configure --with-gcc --with-gnu-ld --with-gnu-as --host=mingw32 --target=mingw32 --prefix= /mingw --enable-threads --disable-nls --enable-languages=c,c++,f77,ada,objc,java --disable-win32-registry --disable-shar ed --enable-sjlj-exceptions --enable-libgcj --disable-java-awt --without-x --enable-java-gc=boehm --disable-libgcj-debug --enable-interpreter --enable-hash-synchronization --enable-libstdcxx-debug Thread model: win32 gcc version 3.4.5 (mingw special) --------------------------------------------------------- An error can be fixed by replacing of string "return x+4;" by "return this->x+4;". But it is fairly bad decision. I suppose that this is a bug (because it compiles by 4.1.1), but I can't use newer compiler, because 3.4.5 is the lattest in MinGW. And I have to use MinGW :( . I hope, that some better workaround or patch for compiler exists, and somebody here can help me. Regards, Mazay.