unordered_map::key_type
The type of an ordering key.
typedef Key key_type;
Remarks
The type is a synonym for the template parameter Key.
Example
// std_tr1__unordered_map__unordered_map_key_type.cpp
// compile with: /EHsc
#include <unordered_map>
#include <iostream>
typedef std::unordered_map<char, int> Mymap;
int main()
{
Mymap c1;
c1.insert(Mymap::value_type('a', 1));
c1.insert(Mymap::value_type('b', 2));
c1.insert(Mymap::value_type('c', 3));
// display contents " [c 3] [b 2] [a 1]"
for (Mymap::const_iterator it = c1.begin();
it != c1.end(); ++it)
std::cout << " [" << it->first << ", " << it->second << "]";
std::cout << std::endl;
// add a value and reinspect
Mymap::key_type key = 'd';
Mymap::mapped_type mapped = 4;
Mymap::value_type val = Mymap::value_type(key, mapped);
c1.insert(val);
for (Mymap::const_iterator it = c1.begin();
it != c1.end(); ++it)
std::cout << " [" << it->first << ", " << it->second << "]";
std::cout << std::endl;
return (0);
}
[c, 3] [b, 2] [a, 1] [d, 4] [c, 3] [b, 2] [a, 1]
Requirements
Header: <unordered_map>
Namespace: std