Re: assignment/initialization of container - map

From:

"mlimber" <mlimber@gmail.com>

Newsgroups:

comp.lang.c++

Date:

18 Jul 2006 14:00:12 -0700

Message-ID:

<1153256412.305895.139620@75g2000cwc.googlegroups.com>

Thomas Tutone wrote:

xuatla wrote:

I want to define a map:

std::map<string, int> myMap;

e.g., the score of students. Then I can assign the value as follows:
myMap["stud1"] = 90;
myMap["stud2"] = 60;
...

My question now is: can I assign the name of many students in one line?
e.g., for array we have the following way:
int myArray[] = { 1, 3, 4, 5 };

Do we have similar way for map?

No.

There are several similar but not identical ways for std::map. See the
other responses in this thread for initializing from an array, and also
consider a helper class that uses method chaining (see the FAQ for more
on that):

template<class K, class V>
class MapInitializer
{
   typedef std::map<K,V> Map;
   Map m_;
public:
   operator Map() const { return m_; }

   MapInitializer& Add( const K& k, const V& v )
   {
     m_[k] = v;
     return *this;
   }
};

const std::map<int,std::string> msgMap
   = MapInitializer<int,std::string>()
     .Add( 1, "Msg 1" )
     .Add( 2, "Msg 2" )
     .Add( 42, "Msg 3" );

Cheers! --M