diff --git a/test/test_block_cache.cpp b/test/test_block_cache.cpp
index 4f587bcbd..bca792bfb 100644
--- a/test/test_block_cache.cpp
+++ b/test/test_block_cache.cpp
@@ -45,6 +45,8 @@ POSSIBILITY OF SUCH DAMAGE.
 
 using namespace lt;
 
+namespace {
+
 struct test_storage_impl : storage_interface
 {
 	explicit test_storage_impl(file_storage const& fs) : storage_interface(fs) {}
@@ -463,6 +465,8 @@ void test_unaligned_read()
 	bc.clear(jobs);
 }
 
+} // anonymous namespace
+
 TORRENT_TEST(block_cache)
 {
 	test_write();
diff --git a/test/test_fast_extension.cpp b/test/test_fast_extension.cpp
index 75d26c2a7..915eccc45 100644
--- a/test/test_fast_extension.cpp
+++ b/test/test_fast_extension.cpp
@@ -54,6 +54,8 @@ POSSIBILITY OF SUCH DAMAGE.
 using namespace lt;
 using namespace std::placeholders;
 
+namespace {
+
 void log(char const* fmt, ...)
 {
 	va_list v;
@@ -469,6 +471,8 @@ std::shared_ptr<torrent_info> setup_peer(tcp::socket& s, sha1_hash& ih
 	return t;
 }
 
+} // anonymous namespace
+
 // makes sure that pieces that are allowed and then
 // rejected aren't requested again
 TORRENT_TEST(reject_fast)
diff --git a/test/test_ip_voter.cpp b/test/test_ip_voter.cpp
index fd15c6ed7..4f22154ea 100644
--- a/test/test_ip_voter.cpp
+++ b/test/test_ip_voter.cpp
@@ -42,6 +42,8 @@ POSSIBILITY OF SUCH DAMAGE.
 
 using namespace lt;
 
+namespace {
+
 bool cast_vote(ip_voter& ipv, address ext_ip, address voter)
 {
 	bool new_ip = ipv.cast_vote(ext_ip, aux::session_interface::source_dht, voter);
@@ -56,6 +58,8 @@ bool cast_vote(ip_voter& ipv, address ext_ip, address voter)
 	return new_ip;
 }
 
+} // anonymous namespace
+
 // test the case where every time we get a new IP. Make sure
 // we don't flap
 TORRENT_TEST(test_random)
diff --git a/test/test_lsd.cpp b/test/test_lsd.cpp
index b85c708a6..7734eb71f 100644
--- a/test/test_lsd.cpp
+++ b/test/test_lsd.cpp
@@ -41,6 +41,8 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "setup_transfer.hpp"
 #include <iostream>
 
+namespace {
+
 void test_lsd()
 {
 	using namespace lt;
@@ -97,6 +99,8 @@ void test_lsd()
 	p2 = ses2.abort();
 }
 
+} // anonymous namespace
+
 TORRENT_TEST(lsd)
 {
 	using namespace lt;
diff --git a/test/test_remap_files.cpp b/test/test_remap_files.cpp
index 41918a9ce..84d4e53ef 100644
--- a/test/test_remap_files.cpp
+++ b/test/test_remap_files.cpp
@@ -51,7 +51,7 @@ namespace {
 
 bool all_of(std::vector<bool> const& v)
 {
-	return std::all_of(v.begin(), v.end(), [](bool v){ return v; });
+	return std::all_of(v.begin(), v.end(), [](bool val){ return val; });
 }
 
 void test_remap_files(storage_mode_t storage_mode = storage_mode_sparse)
@@ -109,9 +109,9 @@ void test_remap_files(storage_mode_t storage_mode = storage_mode_sparse)
 
 	// wait for all alerts to come back and verify the data against the expected
 	// piece data
-	aux::vector<bool, piece_index_t> pieces(fs.num_pieces(), false);
-	aux::vector<bool, piece_index_t> passed(fs.num_pieces(), false);
-	aux::vector<bool, file_index_t> files(fs.num_files(), false);
+	aux::vector<bool, piece_index_t> pieces(std::size_t(fs.num_pieces()), false);
+	aux::vector<bool, piece_index_t> passed(std::size_t(fs.num_pieces()), false);
+	aux::vector<bool, file_index_t> files(std::size_t(fs.num_files()), false);
 
 	while (!all_of(pieces) || !all_of(passed) || !all_of(files))
 	{
@@ -132,7 +132,7 @@ void test_remap_files(storage_mode_t storage_mode = storage_mode_sparse)
 				TEST_EQUAL(t->piece_size(idx), rp->size);
 
 				std::vector<char> const piece = generate_piece(idx, t->piece_size(idx));
-				TEST_CHECK(memcmp(rp->buffer.get(), piece.data(), rp->size) == 0);
+				TEST_CHECK(std::memcmp(rp->buffer.get(), piece.data(), std::size_t(rp->size)) == 0);
 				TEST_CHECK(pieces[idx] == false);
 				pieces[idx] = true;
 			}
@@ -187,8 +187,8 @@ void test_remap_files(storage_mode_t storage_mode = storage_mode_sparse)
 
 	for (int i = 0; i < 50; ++i)
 	{
-		torrent_status st = tor1.status();
-		if (st.is_seeding) break;
+		torrent_status st1 = tor1.status();
+		if (st1.is_seeding) break;
 		std::this_thread::sleep_for(lt::milliseconds(100));
 		print_alerts(ses, "ses");
 	}
diff --git a/test/test_remove_torrent.cpp b/test/test_remove_torrent.cpp
index faf203490..b20d09eb9 100644
--- a/test/test_remove_torrent.cpp
+++ b/test/test_remove_torrent.cpp
@@ -49,6 +49,8 @@ using namespace libtorrent;
 namespace lt = libtorrent;
 using std::ignore;
 
+namespace {
+
 enum test_case {
 	complete_download,
 	partial_download,
@@ -167,6 +169,8 @@ void test_remove_torrent(remove_flags_t const remove_options
 	sp.push_back(ses2.abort());
 }
 
+} // anonymous namespace
+
 TORRENT_TEST(remove_torrent)
 {
 	test_remove_torrent({});
diff --git a/test/test_resolve_links.cpp b/test/test_resolve_links.cpp
index e1028a3d8..c3c7e6d26 100644
--- a/test/test_resolve_links.cpp
+++ b/test/test_resolve_links.cpp
@@ -119,15 +119,15 @@ TORRENT_TEST(resolve_links)
 		if (num_matches > e.expected_matches)
 		{
 			file_storage const& fs = ti1->files();
-			for (file_index_t i{0}; i != links.end_index(); ++i)
+			for (file_index_t idx{0}; idx != links.end_index(); ++idx)
 			{
-				TORRENT_ASSERT(i < file_index_t{fs.num_files()});
+				TORRENT_ASSERT(idx < file_index_t{fs.num_files()});
 				std::printf("%*s --> %s : %d\n"
-					, int(fs.file_name(i).size())
-					, fs.file_name(i).data()
-					, links[i].ti
-					? aux::to_hex(links[i].ti->info_hash()).c_str()
-					: "", static_cast<int>(links[i].file_idx));
+					, int(fs.file_name(idx).size())
+					, fs.file_name(idx).data()
+					, links[idx].ti
+					? aux::to_hex(links[idx].ti->info_hash()).c_str()
+					: "", static_cast<int>(links[idx].file_idx));
 			}
 		}
 
diff --git a/test/test_resume.cpp b/test/test_resume.cpp
index 7d7e3a2a2..f9553c6f4 100644
--- a/test/test_resume.cpp
+++ b/test/test_resume.cpp
@@ -52,6 +52,8 @@ POSSIBILITY OF SUCH DAMAGE.
 
 using namespace lt;
 
+namespace {
+
 torrent_flags_t const flags_mask
 	= torrent_flags::sequential_download
 	| torrent_flags::paused
@@ -77,7 +79,7 @@ std::shared_ptr<torrent_info> generate_torrent()
 	for (piece_index_t i(0); i < fs.end_piece(); ++i)
 	{
 		sha1_hash ph;
-		for (int k = 0; k < 20; ++k) ph[k] = lt::random(0xff);
+		aux::random_bytes(ph);
 		t.set_hash(i, ph);
 	}
 
@@ -94,8 +96,8 @@ std::vector<char> generate_resume_data(torrent_info* ti
 	rd["file-format"] = "libtorrent resume file";
 	rd["file-version"] = 1;
 	rd["info-hash"] = ti->info_hash().to_string();
-	rd["blocks per piece"] = (std::max)(1, ti->piece_length() / 0x4000);
-	rd["pieces"] = std::string(ti->num_pieces(), '\x01');
+	rd["blocks per piece"] = std::max(1, ti->piece_length() / 0x4000);
+	rd["pieces"] = std::string(std::size_t(ti->num_pieces()), '\x01');
 
 	rd["total_uploaded"] = 1337;
 	rd["total_downloaded"] = 1338;
@@ -117,7 +119,7 @@ std::vector<char> generate_resume_data(torrent_info* ti
 			file_prio.push_back(entry(file_priorities[i] - '0'));
 	}
 
-	rd["piece_priority"] = std::string(ti->num_pieces(), '\x01');
+	rd["piece_priority"] = std::string(std::size_t(ti->num_pieces()), '\x01');
 	rd["auto_managed"] = 0;
 	rd["sequential_download"] = 0;
 	rd["paused"] = 0;
@@ -187,7 +189,7 @@ torrent_handle test_resume_flags(lt::session& ses
 	{
 		aux::vector<download_priority_t, file_index_t> priorities_vector;
 		for (int i = 0; file_priorities[i]; ++i)
-			priorities_vector.push_back(download_priority_t(file_priorities[i] - '0'));
+			priorities_vector.push_back(download_priority_t(aux::numeric_cast<std::uint8_t>(file_priorities[i] - '0')));
 
 		p.file_priorities = priorities_vector;
 	}
@@ -274,6 +276,8 @@ void test_piece_priorities(bool test_deprecated = false)
 	TEST_EQUAL(h.piece_priority(piece_index_t(ti->num_pieces()-1)), 0_pri);
 }
 
+} // anonymous namespace
+
 #ifndef TORRENT_NO_DEPRECATE
 TORRENT_TEST(piece_priorities_deprecated)
 {
@@ -296,9 +300,9 @@ TORRENT_TEST(piece_slots)
 	{
 		std::vector<char> a(128 * 1024 * 8);
 		std::vector<char> b(128 * 1024);
-		std::ofstream("add_torrent_params_test/test_resume/tmp1").write(a.data(), a.size());
-		std::ofstream("add_torrent_params_test/test_resume/tmp2").write(b.data(), b.size());
-		std::ofstream("add_torrent_params_test/test_resume/tmp3").write(b.data(), b.size());
+		std::ofstream("add_torrent_params_test/test_resume/tmp1").write(a.data(), std::streamsize(a.size()));
+		std::ofstream("add_torrent_params_test/test_resume/tmp2").write(b.data(), std::streamsize(b.size()));
+		std::ofstream("add_torrent_params_test/test_resume/tmp3").write(b.data(), std::streamsize(b.size()));
 	}
 
 	add_torrent_params p;
@@ -353,9 +357,9 @@ void test_piece_slots_seed(settings_pack const& sett)
 	{
 		std::vector<char> a(128 * 1024 * 8);
 		std::vector<char> b(128 * 1024);
-		std::ofstream("add_torrent_params_test/test_resume/tmp1").write(a.data(), a.size());
-		std::ofstream("add_torrent_params_test/test_resume/tmp2").write(b.data(), b.size());
-		std::ofstream("add_torrent_params_test/test_resume/tmp3").write(b.data(), b.size());
+		std::ofstream("add_torrent_params_test/test_resume/tmp1").write(a.data(), std::streamsize(a.size()));
+		std::ofstream("add_torrent_params_test/test_resume/tmp2").write(b.data(), std::streamsize(b.size()));
+		std::ofstream("add_torrent_params_test/test_resume/tmp3").write(b.data(), std::streamsize(b.size()));
 	}
 
 	add_torrent_params p;
@@ -838,10 +842,10 @@ void test_zero_file_prio(bool test_deprecated = false)
 		file_prio.push_back(entry(0));
 	}
 
-	std::string pieces(ti->num_pieces(), '\x01');
+	std::string pieces(std::size_t(ti->num_pieces()), '\x01');
 	rd["pieces"] = pieces;
 
-	std::string pieces_prio(ti->num_pieces(), '\x01');
+	std::string pieces_prio(std::size_t(ti->num_pieces()), '\x01');
 	rd["piece_priority"] = pieces_prio;
 
 	std::vector<char> resume_data;
@@ -968,14 +972,14 @@ void test_seed_mode(test_mode_t const flags)
 		}
 	}
 
-	std::string pieces(ti->num_pieces(), '\x01');
+	std::string pieces(std::size_t(ti->num_pieces()), '\x01');
 	if (flags & test_mode::pieces_have)
 	{
 		pieces[0] = '\0';
 	}
 	rd["pieces"] = pieces;
 
-	std::string pieces_prio(ti->num_pieces(), '\x01');
+	std::string pieces_prio(std::size_t(ti->num_pieces()), '\x01');
 	if (flags & test_mode::piece_prio)
 	{
 		pieces_prio[0] = '\0';
diff --git a/test/test_session.cpp b/test/test_session.cpp
index c6c4cb800..b82ac6f1a 100644
--- a/test/test_session.cpp
+++ b/test/test_session.cpp
@@ -217,7 +217,7 @@ TORRENT_TEST(session_stats)
 	// make sure every stat index is represented in the stats_metric vector
 	for (int i = 0; i < int(stats.size()); ++i)
 	{
-		TEST_EQUAL(stats[i].value_index, i);
+		TEST_EQUAL(stats[std::size_t(i)].value_index, i);
 	}
 
 	TEST_EQUAL(lt::find_metric_idx("peer.incoming_connections")
@@ -468,7 +468,6 @@ auto const count_dht_inits = [](session& ses)
 		}
 		if (num <= 0) return count;
 	}
-	return count;
 };
 
 TORRENT_TEST(init_dht_default_bootstrap)
diff --git a/test/test_storage.cpp b/test/test_storage.cpp
index e5ea10f15..a3ac9717d 100644
--- a/test/test_storage.cpp
+++ b/test/test_storage.cpp
@@ -58,23 +58,11 @@ POSSIBILITY OF SUCH DAMAGE.
 using namespace std::placeholders;
 using namespace lt;
 
+namespace {
+
 std::size_t const piece_size = 16 * 1024 * 16;
 std::size_t const half = piece_size / 2;
 
-void signal_bool(bool* b, char const* string)
-{
-	*b = true;
-	std::cout << time_now_string() << " " << string << std::endl;
-}
-
-void on_read_piece(int ret, disk_io_job const& j, char const* data, int size)
-{
-	std::cout << time_now_string() << " on_read_piece piece: " << j.piece << std::endl;
-	TEST_EQUAL(ret, size);
-	auto& buffer = boost::get<disk_buffer_holder>(j.argument);
-	if (ret > 0) TEST_CHECK(std::equal(buffer.get(), buffer.get() + ret, data));
-}
-
 void on_check_resume_data(status_t const status, storage_error const& error, bool* done)
 {
 	std::cout << time_now_string() << " on_check_resume_data ret: "
@@ -746,6 +734,8 @@ void test_fastresume(bool const test_deprecated)
 		<< "': " << ec.message() << std::endl;
 }
 
+} // anonymous namespace
+
 TORRENT_TEST(fastresume)
 {
 	test_fastresume(false);
diff --git a/test/test_torrent_info.cpp b/test/test_torrent_info.cpp
index 53bf928f1..2c8d5820a 100644
--- a/test/test_torrent_info.cpp
+++ b/test/test_torrent_info.cpp
@@ -830,24 +830,24 @@ TORRENT_TEST(parse_torrents)
 		}
 
 		file_storage const& fs = ti->files();
-		for (file_index_t i{0}; i != file_index_t(fs.num_files()); ++i)
+		for (file_index_t idx{0}; idx != file_index_t(fs.num_files()); ++idx)
 		{
-			piece_index_t const first = ti->map_file(i, 0, 0).piece;
-			piece_index_t const last = ti->map_file(i, std::max(fs.file_size(i)-1, std::int64_t(0)), 0).piece;
-			file_flags_t const flags = fs.file_flags(i);
-			sha1_hash const ih = fs.hash(i);
+			piece_index_t const first = ti->map_file(idx, 0, 0).piece;
+			piece_index_t const last = ti->map_file(idx, std::max(fs.file_size(idx)-1, std::int64_t(0)), 0).piece;
+			file_flags_t const flags = fs.file_flags(idx);
+			sha1_hash const ih = fs.hash(idx);
 			std::printf("  %11" PRId64 " %c%c%c%c [ %4d, %4d ] %7u %s %s %s%s\n"
-				, fs.file_size(i)
+				, fs.file_size(idx)
 				, (flags & file_storage::flag_pad_file)?'p':'-'
 				, (flags & file_storage::flag_executable)?'x':'-'
 				, (flags & file_storage::flag_hidden)?'h':'-'
 				, (flags & file_storage::flag_symlink)?'l':'-'
 				, static_cast<int>(first), static_cast<int>(last)
-				, std::uint32_t(fs.mtime(i))
+				, std::uint32_t(fs.mtime(idx))
 				, ih != sha1_hash(nullptr) ? aux::to_hex(ih).c_str() : ""
-				, fs.file_path(i).c_str()
+				, fs.file_path(idx).c_str()
 				, flags & file_storage::flag_symlink ? "-> ": ""
-				, flags & file_storage::flag_symlink ? fs.symlink(i).c_str() : "");
+				, flags & file_storage::flag_symlink ? fs.symlink(idx).c_str() : "");
 		}
 	}
 
@@ -911,7 +911,7 @@ void test_resolve_duplicates(int test_case)
 
 	torrent_info ti(tmp, from_span);
 
-	std::vector<aux::vector<char const*, file_index_t>> const filenames
+	aux::vector<aux::vector<char const*, file_index_t>> const filenames
 	{
 		{ // case 0
 			"test/temporary.txt",
@@ -1017,7 +1017,7 @@ TORRENT_TEST(copy)
 	// clear out the  buffer for a, just to make sure b doesn't have any
 	// references into it by mistake
 	int s = a->metadata_size();
-	std::memset(a->metadata().get(), 0, s);
+	std::memset(a->metadata().get(), 0, std::size_t(s));
 
 	a.reset();
 
diff --git a/test/test_transfer.cpp b/test/test_transfer.cpp
index dd503357a..ffb803235 100644
--- a/test/test_transfer.cpp
+++ b/test/test_transfer.cpp
@@ -53,6 +53,8 @@ using namespace lt;
 
 using std::ignore;
 
+namespace {
+
 auto const mask = alert::all_categories
 	& ~(alert::performance_warning | alert::stats_notification);
 
@@ -77,8 +79,8 @@ struct test_storage : default_storage
 		, m_limit(16 * 1024 * 2)
 	{}
 
-	void set_file_priority(aux::vector<download_priority_t, file_index_t> const& p
-		, storage_error& ec) override {}
+	void set_file_priority(aux::vector<download_priority_t, file_index_t> const&
+		, storage_error&) override {}
 
 	void set_limit(int lim)
 	{
@@ -175,21 +177,21 @@ void test_transfer(int proxy_type, settings_pack const& sett
 	{
 		proxy_port = start_proxy(proxy_type);
 
-		settings_pack pack;
-		pack.set_str(settings_pack::proxy_username, "testuser");
-		pack.set_str(settings_pack::proxy_password, "testpass");
-		pack.set_int(settings_pack::proxy_type, proxy_type);
-		pack.set_int(settings_pack::proxy_port, proxy_port);
-		pack.set_bool(settings_pack::force_proxy, true);
+		settings_pack pack_p;
+		pack_p.set_str(settings_pack::proxy_username, "testuser");
+		pack_p.set_str(settings_pack::proxy_password, "testpass");
+		pack_p.set_int(settings_pack::proxy_type, proxy_type);
+		pack_p.set_int(settings_pack::proxy_port, proxy_port);
+		pack_p.set_bool(settings_pack::force_proxy, true);
 
 		// test resetting the proxy in quick succession.
 		// specifically the udp_socket connecting to a new
 		// socks5 proxy while having one connection attempt
 		// in progress.
-		pack.set_str(settings_pack::proxy_hostname, "5.6.7.8");
-		ses1.apply_settings(pack);
-		pack.set_str(settings_pack::proxy_hostname, "127.0.0.1");
-		ses1.apply_settings(pack);
+		pack_p.set_str(settings_pack::proxy_hostname, "5.6.7.8");
+		ses1.apply_settings(pack_p);
+		pack_p.set_str(settings_pack::proxy_hostname, "127.0.0.1");
+		ses1.apply_settings(pack_p);
 	}
 
 	pack = sett;
@@ -264,7 +266,7 @@ void test_transfer(int proxy_type, settings_pack const& sett
 		, (flags & disk_full) ? &addp : &params);
 
 	int num_pieces = tor2.torrent_file()->num_pieces();
-	std::vector<int> priorities(num_pieces, 1);
+	std::vector<int> priorities(std::size_t(num_pieces), 1);
 
 	int upload_mode_timer = 0;
 
@@ -319,7 +321,7 @@ void test_transfer(int proxy_type, settings_pack const& sett
 			&& ++upload_mode_timer > 10)
 		{
 			flags &= ~disk_full;
-			((test_storage*)tor2.get_storage_impl())->set_limit(16 * 1024 * 1024);
+			static_cast<test_storage*>(tor2.get_storage_impl())->set_limit(16 * 1024 * 1024);
 
 			// if we reset the upload mode too soon, there may be more disk
 			// jobs failing right after, putting us back in upload mode. So,
@@ -340,8 +342,8 @@ void test_transfer(int proxy_type, settings_pack const& sett
 			// at this point we probably disconnected the seed
 			// so we need to reconnect as well
 			std::printf("%s: reconnecting peer\n", time_now_string());
-			error_code ec;
-			tor2.connect_peer(tcp::endpoint(address::from_string("127.0.0.1", ec)
+			error_code ec2;
+			tor2.connect_peer(tcp::endpoint(address::from_string("127.0.0.1", ec2)
 				, ses1.listen_port()));
 
 			TEST_CHECK(tor2.status().is_finished == false);
@@ -387,6 +389,8 @@ void cleanup()
 	remove_all("tmp2_transfer_moved", ec);
 }
 
+} // anonymous namespace
+
 #ifndef TORRENT_NO_DEPRECATE
 TORRENT_TEST(no_contiguous_buffers)
 {
diff --git a/test/test_upnp.cpp b/test/test_upnp.cpp
index 81f5d3441..0dd860e72 100644
--- a/test/test_upnp.cpp
+++ b/test/test_upnp.cpp
@@ -119,7 +119,7 @@ std::list<callback_info> callbacks;
 
 namespace // TODO: remove this nested namespace
 {
-	struct upnp_callback : aux::portmap_callback
+	struct upnp_callback final : aux::portmap_callback
 	{
 		void on_port_mapping(port_mapping_t const mapping
 			, address const& ip, int port
@@ -134,12 +134,12 @@ namespace // TODO: remove this nested namespace
 				<< ", error: \"" << err.message() << "\"\n";
 		}
 	#ifndef TORRENT_DISABLE_LOGGING
-		virtual bool should_log_portmap(portmap_transport) const override
+		bool should_log_portmap(portmap_transport) const override
 		{
 			return true;
 		}
 
-		virtual void log_portmap(portmap_transport, char const* msg) const override
+		void log_portmap(portmap_transport, char const* msg) const override
 		{
 			std::cout << "UPnP: " << msg << std::endl;
 			//TODO: store the log and verify that some key messages are there