Re: How to make a template class-friend function

On 17/01/2015 13:19, Victor Bazarov wrote:


Ok, I compiled the site example, and it works. So obviously in my code
there is something I cannot find. I ll try to double check..

site example which works:

template<typename T> class Foo; // pre-declare the template class itself
template<typename T> Foo<T> operator+ (const Foo<T>& lhs, const Foo<T>&
rhs);

template<typename T>
class Foo {
public:
   Foo(T const& value = T());
   friend Foo<T> operator+ <> (const Foo<T>& lhs, const Foo<T>& rhs);
private:
   T value_;
};

template<typename T>
Foo<T>::Foo(T const& value)
   : value_(value)
{ }

template<typename T>
Foo<T> operator+ (const Foo<T>& lhs, const Foo<T>& rhs)
{ return Foo<T>(lhs.value_ + rhs.value_); }