Method hash

docopt_private.h:203–210

		}

		virtual size_t hash() const override {
			size_t seed = typeid(*this).hash_code();
			hash_combine(seed, fChildren.size());
			for(auto const& child : fChildren) {
				hash_combine(seed, child->hash());
			}
			return seed;
		}
	private:
		void fix_repeating_arguments();