http://y6gnjkv2xrjfb7qgs3kmsfyw5qwe7avjvvrnh7wpz5hvtrocm4rbetid.onion/page/2
However, this seemed a frequent case to me, and I was curious to see if there was a way to still take advantage of the optimized algorithms provided by the containers. Indeed, there is ! But it was added only since C++14 . After implementing bool operator<(const Other &, const Key &) , you can pass std::less<> as a comparator to your container instead of the default std::less<Key> .