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Dag-Erling Smørgrav · Guest

{ FAQ section 13 explains many aspects of operator overloading. -mod }

What, if any, is the difference between defining an overloaded operator
as a member of a class, and defining it as a global function?

For instance, in the GNU STL (derived from HP / SGI), the equality
comparison for std::vector is defined as follows:

template<typename _Tp, typename _Alloc>
inline bool
operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
{ return (__x.size() == __y.size()
&& std::equal(__x.begin(), __x.end(), __y.begin())); }

Could it not have been defined as

inline bool
operator==(const vector<_Tp, _Alloc>& __other)
{ return (size() == __other.size()
&& std::equal(begin(), end(), __other.begin())); }

within template<_Tp, _Alloc> class vector { } intead?

DES
--
Dag-Erling Smørgrav - des (AT) des (DOT) no

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