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std::vector<T>::iterator not recognised?

I'm attempting to use std::find() to located a specific element in a std::vector, and for some reason, When I try to create a std::vector<T>::iterator, g++ complains.

Does anyone know my problem?

#include <vector>

#include <iostream>

#include <cstddef>

#include <stdexcept>

#include <string>

#include <iterator>

#include <algorithm>



template<typename T, size_t capacity=5>

class Basket {

    private:

        const size_t m_capacity;

        std::vector<T> m_items;

    public:

        class CapacityError : public std::length_error {

            public:

                CapacityError(const std::string &msg)

                    : length_error(msg) {

                }

        };



        class ItemNotFoundError : public std::invalid_argument {

            public:

                ItemNotFoundError(const std::string &msg)

                    : invalid_argument(msg) {

                }

        };

        

        Basket()

            : m_capacity(capacity),

              m_items(0) {

        }



        void add_item(const T &item) {

            if(m_items.size() + 1 > m_capacity)

                throw CapacityError("The Basket it full!");

            else

                m_items.push_back(item);

        }



        void remove_item(const T &item) {

            std::vector<T>::iterator pos;

            pos = find(m_items.begin(), m_items.end(), item);



            if(pos != m_items.end())

                m_items.erase(pos);

            else

                throw ItemNotFoundError("The specified item was not found in the Basket.");

        }

};



int main() {

    Basket<int> basket;



    return 0;

}

ERRORS

basket.cpp: In member function ‘void Basket<T, capacity>::remove_item(const T&)’:

basket.cpp:42: error: expected `;' before ‘pos’

basket.cpp:43: error: ‘pos’ was not declared in this scope

Compiles fine in VC++ 2005, but not Dev-C++ (with g++.exe). It works OK if you typename it thought.

typename std::vector<T>::iterator iter = 

  std::find(m_items.begin(), m_items.end(), item);

>std::vector<T>::iterator pos;
vector<T>::iterator is a type that depends on a template argument (T being that argument). In such a case you have to specify that you're referring to a type rather than a "thing" by using the typename keyword:

typename std::vector<T>::iterator pos;

Thanks Narue and Cache. :)

There is so much more to C++ then I once thought. I know the basics, but some template and class features are incredibly complicated :eek:.

>some template and class features are incredibly complicated
I think that templates are the most complicated feature of C++. It's basically a turing complete sub-language. There's a lot of power, but only if you can wrap your brain around it. :)

Quote:

Originally Posted by Cache

Compiles fine in VC++ 2005, but not Dev-C++ (with g++.exe). It works OK if you typename it thought.

On a side not, is it standards compliant to compile without the typename? I have done some pretty heavy template stuff with GCC 4.0.x and it always requires typename, the error messages even tell you to use it. I was quite supprised to see a helpful error message from the compilier.

>On a side not, is it standards compliant to compile without the typename?
No, in strict mode, a compliant compiler should produce a diagnostic message.

Quote:

Originally Posted by Narue

No, in strict mode, a compliant compiler should produce a diagnostic message.

You're right but, at the risk of being picky .... I would probably make the statement outside in, whereas you have made it inside out.

A compliant compiler should produce a diagnostic. A compiler that is non-compliant may not. Some compilers, by default, are a bit relaxed about standard compliance (i.e. the "strict mode", as you describe it, is disabled by default).