• fallback_popcount() : tsl::detail_popcount
• fallback_popcountll() : tsl::detail_popcount
• is_power_of_two() : tsl::detail_sparse_hash
• popcount() : tsl::detail_popcount
• popcountll() : tsl::detail_popcount
• round_up_to_power_of_two() : tsl::detail_sparse_hash