Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Function hash_value

boost::hash_value —

template<typename A, typename B> 
  std::size_t hash_value(std::pair<A, B> const & val);

Effects:

size_t seed = 0;
hash_combine(seed, val.first);
hash_combine(seed, val.second);
return seed;

Throws: Only throws if hash_value(A) or hash_value(B) throws.
Notes: This is an extension to TR1