[ox/std] Remove unnecessary copying from HashMap::expand

(synced from 6bfe184261)

src/ox/std/hashmap.hpp

@@ -212,7 +212,7 @@ template<typename K, typename T>
 constexpr void HashMap<K, T>::expand() {
 	Vector<Pair*> r;
 	for (std::size_t i = 0; i < m_keys.size(); ++i) {
-		K k{m_keys[i]};
+		auto const&k = m_keys[i];
 		access(r, k) = std::move(access(m_pairs, k));
 	}
 	m_pairs = std::move(r);