set< pair<string, string> > or multiset?

From: Mario Contestabile (mario_at_zks.net)
Date: 09/14/04 

Date: Tue, 14 Sep 2004 09:52:43 -0400

Greetings,

Buddy of mine's code has a set<> (this is with the dinkum library 2.32) and
in it he places a pair<> of strings.

This is what it looks like: set< pair<string, string> >

Since the default comparison function for set is less, as seen here from
<functional>

template<class _Ty>
 struct less : binary_function<_Ty, _Ty, bool> {
 bool operator()(const _Ty& _X, const _Ty& _Y) const
  {return (_X < _Y); }
 };

I was wondering just how will his set<> be ordered ? Will it be ordered on
the string comparison for the pair.first or pair.second?

Wouldn't the use of a multiset be better suited? A multiset is for
(possibly) non unique keys, and a set is for unique keys.

The way he has it written, items are inserted into the set like so

x = std::make_pair( strKey, strValue );
hisSet.insert( x );

but strKey is not unique at all, there are several instances of the same
string.

thanx

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