Hello daniweb. Seems like this site is amongst the latest and the greatest in programming and software development.


Attempt to compile with gcc: C:\>gcc -o ywordf ywordf.cpp

ywordf.cpp: In function `int main(int, char**)':
ywordf.cpp:30: error: no match for 'operator!=' in 'i != __gnu_norm::multimap<_Key, _Tp, _Compare, _Alloc>::rend() [with _Key = size_t, _Tp = std::string, _Compare = std::less<size_t>, _Alloc = std::allocator<std::pair<const size_t, std::string> >]()'


#include <set>
#include <map>
#include <fstream>
#include <iostream>
#include <iterator>
#include <utility>

using namespace std;

int main(int ac, char** av)
if(ac != 2)
cout << "Usage: " << av[0] << " filename" << endl;
return 1;
cout << "Reading file " << av[1] << endl;
ifstream f(av[1]);

// read and count words
istream_iterator<string> i(f);
multiset<string> s(i, istream_iterator<string>());

// sort by count
multimap<size_t, string> wordstats;
for(multiset<string>::const_iterator i = s.begin(); i != s.end(); i = s.upper_bound(*i))
wordstats.insert( make_pair( s.count(*i), *i ));

// output in decreasing order
for( multimap<size_t, string>::const_reverse_iterator i = wordstats.rbegin(); i != wordstats.rend(); ++i)
cout << " word " << i->second << " found " << i->first << " times " << endl;

The error is in line 28, which is:

for( multimap<size_t, string>::const_reverse_iterator i = wordstats.rbegin(); i != wordstats.rend(); ++i)


What on earth am I doing wrong? What do I need to change in this line?

I've never seen this error before, but I believe it has something to do with having or not having a const value in the for(multimap( paramaters.

Help! and Thank You! I would be happy to post the purpose of my code, but its not necessary. People far more experienced than I can tell exactly what I'm doing.


6 Years
Discussion Span
Last Post by aeolusaether

Your code compiles fine on my machine.

g++ (GCC) 4.4.1 20090725 (Red Hat 4.4.1-2)


I can confirm that using G++ does compile the code on my machine. Apparently there was an STL issue or something wrong specific to my machine.


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