The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference, 2nd Edition
by Nicolai M. Josuttis, Addison Wesley Longman, 2012
Copyright © 2012 by Pearson Education, Inc. and Nicolai M. Josuttis
#include <iostream>
#include <iomanip>
#include <utility>
#include <iterator>
#include <typeinfo>
// generic output for pairs (map elements)
template <typename T1, typename T2>
std::ostream& operator << (std::ostream& strm, const std::pair<T1,T2>& p)
{
return strm << "[" << p.first << "," << p.second << "]";
}
template <typename T>
void printHashTableState (const T& cont)
{
// basic layout data:
std::cout << "size: " << cont.size() << "\n";
std::cout << "buckets: " << cont.bucket_count() << "\n";
std::cout << "load factor: " << cont.load_factor() << "\n";
std::cout << "max load factor: " << cont.max_load_factor() << "\n";
// iterator category:
if (typeid(typename std::iterator_traits
<typename T::iterator>::iterator_category)
== typeid(std::bidirectional_iterator_tag)) {
std::cout << "chaining style: doubly-linked" << "\n";
}
else {
std::cout << "chaining style: singly-linked" << "\n";
}
// elements per bucket:
std::cout << "data: " << "\n";
for (auto idx=0u; idx != cont.bucket_count(); ++idx) {
std::cout << " b[" << std::setw(2) << idx << "]: ";
for (auto pos=cont.begin(idx); pos != cont.end(idx); ++pos) {
std::cout << *pos << " ";
}
std::cout << "\n";
}
std::cout << std::endl;
}