Hello, maybe the c++ gurus out there have an idea. currently i think it is unpossible. i try to use a template a a class member variable, like that: asume a template matrix class template < int cols, int rows> class matrix { // implementation } everything works fine when i'm doing something like matrix<<3,4> mymat; matrix <5,5> quad; but now i try to do it a little more generic i try to build a class, which have a member of this matrix like class MyClass { MyClass(); MyClass(n,n); private: matrix<n,n> }; this means, at runtime, i want to set the size of the matrix. is this possible? this are divers concepts (templates and runtime) , aren't they? thanks c~