how to use a STL map?

[David Loo]

Hi,

I want to use a map to store a list of strings and i dont want a duplicate
string added to the list.
how can I go about this using the STL map?

Thank you.
loodav@hotmailD OTcom
replace the DOT with a periond "." to reply by email thanks

[Noah Roberts]

Re: how to use a STL map?

David Loo wrote:[color=blue]
> Hi,
>
> I want to use a map to store a list of strings and i dont want a duplicate
> string added to the list.
> how can I go about this using the STL map?[/color]

I can't really say without knowing what you want better, but if all you
want is to keep a bunch of unique values use a set.

--
Noah Roberts
- "If you are not outraged, you are not paying attention."

[Philippe Guglielmetti]

Re: how to use a STL map?

"David Loo" wrote:[color=blue]
> I want to use a map to store a list of strings and i dont want a duplicate
> string added to the list. how can I go about this using the STL map?[/color]

a std::map stores pairs of values, ensuring the first element of each stored
pair is unique.
so you can for example do something like:

class unique_strings: public map<string,int> // stores strings without
duplicates, int is dummy
{
typedef pair<string,int > value_type; // normally already defined in
map
// constructors...
bool insert(const string& s) {return insert(value_ty pe(s,1)).parent ;}
// map::insert returns a pair<iterator, bool> result
bool contains(const string& s) const {return find(s)!=end(); } //
map::find returns an iterator to the found pair
};

Note that you can very easily use the <int> term of the pair to store a
number of occurences...
--
Philippe Guglielmetti - www.dynabits.com