Sort a map in C++ by value not by key: map<char, int>

Oops, corection, that should have been

map<int, char>::iterator i2 = tmp.begin();

while (i2 != tmp.end()) {

  cout << i2->first << " <-> " i2->second << endl;

  ++i2;
}

gives me an incomplete output:

for the map:

a 4
b 2
c 2
d 2
f 4

this code gave me:

2 b
4 a

its replacing the 4 f with teh 4 a ... and the 2 c and 2 d with the 2 b...

I hate to say that, but I get

#include <map>
#include <iostream>
using namespace std;

int main () {

map<char, int> table;

table.insert(map<char, int>::value_type('A',23));
table.insert(map<char, int>::value_type('B',2));
table.insert(map<char, int>::value_type('C',26));
table.insert(map<char, int>::value_type('D',12));

map<int, char> tmp;
map<char, int>::iterator i1 = table.begin();

while (i1 != table.end()) {

  tmp.insert(map<char, int>::value_type(i1->second,i1->first));

  ++i1;
}

map<int, char>::iterator i2 = tmp.begin();

while (i2 != tmp.end()) {

  cout << i2->first << " <-> " << i2->second << endl;

  ++i2;
}

return 0;
}

2 <-> B
12 <-> D
23 <-> A
26 <-> C

which to me seems to be what you want.

Joaquín M López Muñoz has build a bimap class which does have the ability to retrieve keys by value.
See following link for more information and source code:

http://www.codeproject.com/vcpp/stl/bimap.asp

jkr and I have answered his question ..

regards,Ahmad;

Little late now, but IMHO, the link I provided really answred the question.
It gives the functionallity the questioner was looking for.