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What is the best way to map two values to one key?
ie An item with a value and bool.
Tried using:
std::map<std::string, std::pair<std::string, bool> > myMap2
But that doesn't seem like the correct solution. Is there a more elegant way to do this?
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The C++ STL map is an associative map between a single key and a single value. In addition, the key must be unique for the given map. The C++ STL also provides a multimap template, which removes the unique key restriction. A single key in a multimap can map to multiple values.
Do you mean cout << mymap[make_pair(1,2)] << endl; ? (1,2) is non-sensical, at least in this context. You must have an std::pair to be used as your key, and that means following what @andre just commented. Yes!
The std::map operator[] returns a reference to the map element identified by 100 (key), which is then overwritten by the pair returned by std::make_pair(10,10). I would suggest: map. insert( std::make_pair( 100, std::make_pair(10,10) ) );
That is indeed the correct solution. More generally, consider using std::tuple instead of std::pair for a uniform interface regardless of the number of values (as std::pair is obviously restricted to two), or boost::tuple if your compiler is too old to ship with a std:: or std::tr1:: implementation.
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Either use std::pair<> as you did, or make a custom struct containing the values you want to store. I'd do the latter in most cases, as the values then have names more descriptive than first and second.
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