Formula used to calculate boost::hash

Question

I would like to know the formula used to calculate the hash values for Boost.Bimap. For example if I want to know and calculate manually for integer 123456, or bit-set 1101001 or character string abcda.

Answer 1

Boost uses Boost::hash for unordered containers, including Bimap. Boost::hash implementations could be found here on Ginhub.

See hash_range for strings, hash_value_signed/unsigned for integers.

You could use this snippet to calculate hash values (use your data type instead of int):

boost::hash<int> hasher;
size_t hash_value = hasher(your_int_key);

You could also create custom hash function for your data types.