Pascal J. Bourguignon wrote:
Ralf Goertz <r_goertz@expires-2006-11-30.arcornews.de> writes:
it doesn't seem to be possible to use transform for maps.
Yes it is possible:
#include <algorithm>
#include <map>
#include <iterator>
#include <vector>
#include <iostream>
using namespace std;
int doit(std::pair<const int,int>& w) {
return w.second+1;
}
int main() {
map<int,int> m;
map<int,int> o;
m[0]=42;
m[3]=33;
m[6]=66;
m[2]=22;
m[4]=44;
vector<int> v(m.size());
transform(m.begin(),m.end(),v.begin(),doit);
copy(v.begin(),v.end(),ostream_iterator<int>(cout," "));
cout<<endl; return(0);
}
/*
-*- mode: compilation; default-directory: "/tmp/" -*-
Compilation started at Mon Mar 16 15:45:08
SRC="/tmp/tm.c++" ; EXE="tm" ; g++ -g3 -ggdb3 -o ${EXE} ${SRC} &&
./${EXE} && echo status = $? 43 23 34 45 67
status = 0
Compilation finished at Mon Mar 16 15:45:09
*/>
doesn't help. What would be the right way to do it?
You need to declare the key const in the pair.
Okay, thanks. But can I also do it *in place* (like I did it with the
vector in the OP).