linux eclipse c++ local namespaces and "std::" - c++

Question

I am trying my first c++ project and am starting small, I think. I am using Eclipse Luna and am trying to take the defaults for build env everywhere that I can. I suspect that the following is vary naive code but you gotta start somewhere.
I will eventually have 4 co/sub projects in this:
Commandline interface to a static lib
".so" lib that will be dynamically loaded into a different, thied party app and uses the static lib
A static library, mentioned above, that does the back end work of the combined app.
A utility class (for now, maybe a small lib later) for utility classes and functions common to the other sub projects.
There are a ton of questions on best practices, namespaces, etc that I would like to ask but I'll keep this short.
I have the following c++ header file:
/*
* Utilities.h
*
*/
#ifndef UTILITIES_H_
#define UTILITIES_H_
// A
namespace UserTrackingUtilities {
// B
#include <string>
#include <exception>
using namespace std;
class MyException: public std::exception {
public:
MyException(std::string ss) : s(ss) {
}
~MyException() throw () {
} // Updated
std::string s;
const char* what() const throw () {
return s.c_str();
}
};
}
#endif /* UTILITIES_H_ */
This is an exception utility (found in a different StackOverflow thread) that I am wrapping in a namespace of my own -- I think.
Eclipse is showing several issues with this header file. I'll start with one: it doesn't like the std::string construct. It doesn't matter if I put the #includes and/or the using statements at point A or B.
I've also tried this with the Linux GCC and ADT tool chains.
Pointers and advice welcome.

Answer 1

#include <string>
#include <exception>
Should be before
namespace UserTrackingUtilities {
BTW:
If you use using namespace std, you can write string instead of std::string.
But I suggest not to use using namespace std to avoid name conflicts and ambiguities.
Update:
Here is a minimal working example:
#include <iostream>
#include <string>
#include <exception>
namespace UserTrackingUtilities {
class MyException: public std::exception {
public:
MyException(std::string ss) : s(ss) {
}
~MyException() throw () {
} // Updated
std::string s;
const char* what() const throw () {
return s.c_str();
}
};
}
int main()
{
UserTrackingUtilities::MyException ex("Hello World");
std::cout << ex.what() << std::endl;
return 0;
}