Question

I have a container object that is templatized. I am trying to make a specialized constructor for float versions. Problem is, when the compiler attempts to compile the second object that uses the float version, I get a multiple definition of error.

NOTES: The entire class in in the h file. The file is wrapped with a definition (#ifndef, #define, and #endif). g++ version 3.4.6. This compiles fine with other compilers, e.g. Intel’s icc.

Code is similar to the following:

template <typename T>
class Container {
public:
   Container();
   virtual ~Container() {}
private:
   std::vector<T> data;
   // other members
};

template <> Container<float>::Container() {
   // do something special
}

template <typename T> Container<T>::Container() {
   // do default initialization
}

Any ideas? Thanks!

EDIT The objects being compiled are also going into separate shared objects, not sure if that has something to do with it.

Answer 1

Specializations still must abide by the one-definition rule just like any other non-template method. Either mark it inline or define the method body in a source file (not your header).