Boost, boost::hash_combine, VS, Project

Boost, boost::hash_combine, 

https://www.boost.org/doc/libs/1_55_0/doc/html/hash/combine.html

D:\VC24\Cpp\CppClassic\Ca_Hash_Boost_01\Ca_Hash_Boost_01.vcxproj

When using boost::hash_combine the order of the calls matters.

    std::size_t seed = 0;
    boost::hash_combine(seed, 1);
    boost::hash_combine(seed, 2);

results in a different seed to:

    std::size_t seed = 0;
    boost::hash_combine(seed, 2);
    boost::hash_combine(seed, 1);

If you are calculating a hash value for data where the order of the data doesn't matter in comparisons (e.g. a set) you will have to ensure that the data is always supplied in the same order.