Question

I need a template like this, which work perfectly

template <typename container> void mySuperTempalte (const container myCont) {     //do something here } 

then i want to specialize the above template for std::string so i came up with

template <typename container> void mySuperTempalte (const container<std::string> myCont) {     //check type of container     //do something here } 

which doesnt’t work, and throws an error. I would like to make the second example work and then IF possible i would like to add some code in the template to check if a std::vector/std::deque/std::list was used, to do something differently in each case. So i used templates because 99% of the code is the same for both vectors and deques etc.

Answer 1

If I am understanding your problem correctly you have an algorithm that will work for STL containers vector, deque etc but are trying to write a template specialisation for string. If this is the case then you can write the generalised templated method that you defined in your question:-

template<typename container> void mySuperTempalte( const container &myCont ) {     // Implement STL container code } 

Then for your string specialisation you declare:-

template<> void mySuperTempalte( const container<std::string> &myCont ) {     // Implement the string code } 

For any other specialisation just change the type declaration for myCont. If you really need to do this for the vector and deque containers then make the template parameter the parameter for the type in that container rather than the container itself as Sep suggested.

template<typename C> void mySuperTempalte( const std::vector<C> &myCont) {     // check type of container     // do something here } 

It’s worth trying to avoid this by making your first implementation work with all STL containers to make your life easier, then you only need the specialisation for the string class. Even consider converting your string to a vector to avoid the specialisation all together.

On a side note, I’ve changed the container parameter to a const reference, I assume this is what you want, as you declare the object const anyway, this way you avoid a copy.