[Qt-interest] qhash - user defined key type

[Yifei Li]

Here is the problem I'm having with QHash right now ( Below is a minimal example that will reproduce my problem)

/** Header file from some third-party library */

namespace Test {
class Foo{
public:
   Foo(id);
   int id() const { return m_id; }
private:
   int m_id;
};
}

/** My header file */

using namespace Test;

class Bar{
public:
   void init() 
   {
       Foo f(1);
       indicators[f] = false;
   }
private:
   QHash<Foo, bool>  indicators;
};

//  overload operators so that Foo can be used as a key type
inline bool operator==(const Foo& f1, const Foo&f2)
inline uint qHash(const Foo& f);

/** main.cpp */
int main 
{
    Bar b;
    b.init();
    return 0;
}

/** Failed to compile the above code */
ERROR: no matching function for call to ‘qHash(const Test::Foo&)’

What should I do to get rid of the error? thanks


Yifei