diff --git a/include/libtorrent/Makefile.am b/include/libtorrent/Makefile.am
index 304df702a..bff16eda3 100644
--- a/include/libtorrent/Makefile.am
+++ b/include/libtorrent/Makefile.am
@@ -198,6 +198,7 @@ nobase_include_HEADERS = \
   aux_/alloca.hpp                   \
   aux_/throw.hpp                    \
   aux_/typed_span.hpp               \
+  aux_/array.hpp                    \
   \
   extensions/smart_ban.hpp          \
   extensions/ut_metadata.hpp        \
diff --git a/include/libtorrent/aux_/array.hpp b/include/libtorrent/aux_/array.hpp
new file mode 100644
index 000000000..739e8039c
--- /dev/null
+++ b/include/libtorrent/aux_/array.hpp
@@ -0,0 +1,78 @@
+/*
+
+Copyright (c) 2017, Arvid Norberg, Alden Torres
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in
+      the documentation and/or other materials provided with the distribution.
+    * Neither the name of the author nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#ifndef TORRENT_ARRAY_HPP
+#define TORRENT_ARRAY_HPP
+
+#include <array>
+
+#include "libtorrent/units.hpp"
+#include "libtorrent/assert.hpp"
+
+namespace libtorrent { namespace aux {
+
+	template <typename T, std::size_t Size, typename IndexType = int>
+	struct array : std::array<T, Size>
+	{
+		using base = std::array<T, Size>;
+		using underlying_index = typename underlying_index_t<IndexType>::type;
+
+		array() = default;
+		explicit array(std::array<T, Size>&& arr) : base(arr) {}
+
+		auto operator[](IndexType idx) const -> decltype(this->base::operator[](underlying_index()))
+		{
+			TORRENT_ASSERT(idx >= IndexType(0));
+			TORRENT_ASSERT(idx < end_index());
+			return this->base::operator[](std::size_t(static_cast<underlying_index>(idx)));
+		}
+
+		auto operator[](IndexType idx) -> decltype(this->base::operator[](underlying_index()))
+		{
+			TORRENT_ASSERT(idx >= IndexType(0));
+			TORRENT_ASSERT(idx < end_index());
+			return this->base::operator[](std::size_t(static_cast<underlying_index>(idx)));
+		}
+
+#if !TORRENT_USE_ASSERTS
+		constexpr
+#endif
+		IndexType end_index() const
+		{
+			TORRENT_ASSERT(this->size() <= std::size_t(std::numeric_limits<underlying_index>::max()));
+			return IndexType(static_cast<underlying_index>(this->size()));
+		}
+	};
+
+}}
+
+#endif
diff --git a/include/libtorrent/aux_/unique_ptr.hpp b/include/libtorrent/aux_/unique_ptr.hpp
index 9e7c428c2..ddf7c5112 100644
--- a/include/libtorrent/aux_/unique_ptr.hpp
+++ b/include/libtorrent/aux_/unique_ptr.hpp
@@ -50,7 +50,7 @@ namespace libtorrent { namespace aux {
 		using base = std::unique_ptr<T[]>;
 		using underlying_index = typename underlying_index_t<IndexType>::type;
 
-		unique_ptr() {}
+		unique_ptr() = default;
 		explicit unique_ptr(T* arr) : base(arr) {}
 
 		auto operator[](IndexType idx) const -> decltype(this->base::operator[](underlying_index()))
diff --git a/include/libtorrent/peer_class_set.hpp b/include/libtorrent/peer_class_set.hpp
index d48e423a6..ad2a17a45 100644
--- a/include/libtorrent/peer_class_set.hpp
+++ b/include/libtorrent/peer_class_set.hpp
@@ -34,7 +34,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #define TORRENT_PEER_CLASS_SET_HPP_INCLUDED
 
 #include "libtorrent/peer_class.hpp"
-#include <array>
+#include "libtorrent/aux_/array.hpp"
 
 namespace libtorrent {
 
@@ -50,7 +50,7 @@ namespace libtorrent {
 		peer_class_t class_at(int i) const
 		{
 			TORRENT_ASSERT(i >= 0 && i < int(m_size));
-			return m_class[std::size_t(i)];
+			return m_class[i];
 		}
 
 	private:
@@ -62,7 +62,7 @@ namespace libtorrent {
 		// class IDs. Each ID refers to a an entry in m_ses.m_peer_classes which
 		// holds the metadata about the class. Classes affect bandwidth limits
 		// among other things
-		std::array<peer_class_t, 15> m_class;
+		aux::array<peer_class_t, 15> m_class;
 	};
 }
 
diff --git a/include/libtorrent/peer_list.hpp b/include/libtorrent/peer_list.hpp
index 2f0d60281..b8213eaca 100644
--- a/include/libtorrent/peer_list.hpp
+++ b/include/libtorrent/peer_list.hpp
@@ -34,7 +34,6 @@ POSSIBILITY OF SUCH DAMAGE.
 #define TORRENT_POLICY_HPP_INCLUDED
 
 #include <algorithm>
-#include <deque>
 #include "libtorrent/string_util.hpp" // for allocate_string_copy
 #include "libtorrent/request_blocks.hpp" // for source_rank
 
@@ -47,6 +46,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/config.hpp"
 #include "libtorrent/debug.hpp"
 #include "libtorrent/peer_connection_interface.hpp"
+#include "libtorrent/aux_/deque.hpp"
 
 namespace libtorrent
 {
@@ -167,7 +167,7 @@ namespace libtorrent
 
 		int num_peers() const { return int(m_peers.size()); }
 
-		using peers_t = std::deque<torrent_peer*>;
+		using peers_t = aux::deque<torrent_peer*>;
 		using iterator = peers_t::iterator;
 		using const_iterator = peers_t::const_iterator;
 		iterator begin() { return m_peers.begin(); }
diff --git a/include/libtorrent/performance_counters.hpp b/include/libtorrent/performance_counters.hpp
index a8a6c8159..1ad8316cb 100644
--- a/include/libtorrent/performance_counters.hpp
+++ b/include/libtorrent/performance_counters.hpp
@@ -34,11 +34,11 @@ POSSIBILITY OF SUCH DAMAGE.
 #define TORRENT_PERFORMANCE_COUNTERS_HPP_INCLUDED
 
 #include "libtorrent/config.hpp"
+#include "libtorrent/aux_/array.hpp"
 
 #include <cstdint>
 #include <atomic>
 #include <mutex>
-#include <array>
 
 namespace libtorrent
 {
@@ -449,15 +449,14 @@ namespace libtorrent
 		// of the counters per thread and collect them at convenient
 		// synchronization points
 #ifdef ATOMIC_LLONG_LOCK_FREE
-		std::array<std::atomic<std::int64_t>, num_counters> m_stats_counter;
+		aux::array<std::atomic<std::int64_t>, num_counters> m_stats_counter;
 #else
 		// if the atomic type is't lock-free, use a single lock instead, for
 		// the whole array
 		mutable std::mutex m_mutex;
-		std::array<std::int64_t, num_counters> m_stats_counter;
+		aux::array<std::int64_t, num_counters> m_stats_counter;
 #endif
 	};
 }
 
 #endif
-
diff --git a/src/bt_peer_connection.cpp b/src/bt_peer_connection.cpp
index 3161c6750..e2eb498c3 100644
--- a/src/bt_peer_connection.cpp
+++ b/src/bt_peer_connection.cpp
@@ -2166,10 +2166,11 @@ namespace libtorrent
 		if (should_log(peer_log_alert::outgoing_message))
 		{
 			std::string bitfield_string;
-			bitfield_string.resize(num_pieces);
-			for (int k = 0; k < num_pieces; ++k)
+			std::size_t const n_pieces = aux::numeric_cast<std::size_t>(num_pieces);
+			bitfield_string.resize(n_pieces);
+			for (std::size_t k = 0; k < n_pieces; ++k)
 			{
-				if (msg[5 + k / 8] & (0x80 >> (k % 8))) bitfield_string[k] = '1';
+				if (msg[5 + int(k) / 8] & (0x80 >> (k % 8))) bitfield_string[k] = '1';
 				else bitfield_string[k] = '0';
 			}
 			peer_log(peer_log_alert::outgoing_message, "BITFIELD"
@@ -2877,7 +2878,7 @@ namespace libtorrent
 			{
 				// select a crypto method
 				int allowed_encryption = m_settings.get_int(settings_pack::allowed_enc_level);
-				std::uint32_t crypto_select = crypto_field & allowed_encryption;
+				std::uint32_t crypto_select = crypto_field & std::uint32_t(allowed_encryption);
 
 				// when prefer_rc4 is set, keep the most significant bit
 				// otherwise keep the least significant one
@@ -2907,14 +2908,14 @@ namespace libtorrent
 				}
 
 				// write the pe4 step
-				write_pe4_sync(crypto_select);
+				write_pe4_sync(aux::numeric_cast<int>(crypto_select));
 			}
 			else // is_outgoing()
 			{
 				// check if crypto select is valid
 				int allowed_encryption = m_settings.get_int(settings_pack::allowed_enc_level);
 
-				crypto_field &= allowed_encryption;
+				crypto_field &= std::uint32_t(allowed_encryption);
 				if (crypto_field == 0)
 				{
 					// we don't allow any of the offered encryption levels
diff --git a/src/cpuid.cpp b/src/cpuid.cpp
index 6de1d1836..dd0dce2c9 100644
--- a/src/cpuid.cpp
+++ b/src/cpuid.cpp
@@ -71,7 +71,7 @@ namespace libtorrent { namespace aux
 		__cpuid((int*)info, type);
 
 #elif defined __GNUC__
-		__get_cpuid(type, &info[0], &info[1], &info[2], &info[3]);
+		__get_cpuid(std::uint32_t(type), &info[0], &info[1], &info[2], &info[3]);
 #else
 		TORRENT_UNUSED(type);
 		// for non-x86 and non-amd64, just return zeroes
diff --git a/src/disk_io_thread.cpp b/src/disk_io_thread.cpp
index 503bea6ce..e56e95112 100644
--- a/src/disk_io_thread.cpp
+++ b/src/disk_io_thread.cpp
@@ -51,6 +51,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/debug.hpp"
 #include "libtorrent/units.hpp"
 #include "libtorrent/hasher.hpp"
+#include "libtorrent/aux_/array.hpp"
 
 #include <functional>
 
@@ -3386,7 +3387,7 @@ namespace libtorrent
 		disk_io_job* j = m_completed_jobs.get_all();
 		l.unlock();
 
-		std::array<disk_io_job*, 64> to_delete;
+		aux::array<disk_io_job*, 64> to_delete;
 		int cnt = 0;
 
 		while (j)
diff --git a/src/escape_string.cpp b/src/escape_string.cpp
index c88f75378..e2bdf6544 100644
--- a/src/escape_string.cpp
+++ b/src/escape_string.cpp
@@ -57,6 +57,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/aux_/escape_string.hpp"
 #include "libtorrent/aux_/max_path.hpp" // for TORRENT_MAX_PATH
 #include "libtorrent/string_util.hpp" // for to_string
+#include "libtorrent/aux_/array.hpp"
 
 namespace libtorrent
 {
@@ -245,7 +246,7 @@ namespace libtorrent
 		// first, strip the file:// part.
 		// On windows, we have
 		// to strip the first / as well
-		int num_to_strip = 7;
+		std::size_t num_to_strip = 7;
 #ifdef TORRENT_WINDOWS
 		if (url[7] == '/' || url[7] == '\\') ++num_to_strip;
 #endif
@@ -279,8 +280,8 @@ namespace libtorrent
 			'4', '5', '6', '7', '8', '9', '+', '/'
 		};
 
-		std::array<std::uint8_t, 3> inbuf;
-		std::array<std::uint8_t, 4> outbuf;
+		aux::array<std::uint8_t, 3> inbuf;
+		aux::array<std::uint8_t, 4> outbuf;
 
 		std::string ret;
 		for (std::string::const_iterator i = s.begin(); i != s.end();)
@@ -335,10 +336,10 @@ namespace libtorrent
 		};
 		char const *base32_table = 0 != (flags & string::lowercase) ? base32_table_lowercase : base32_table_canonical;
 
-		static std::array<int const, 6> input_output_mapping = {{0, 2, 4, 5, 7, 8}};
+		static aux::array<int, 6> const input_output_mapping{{{0, 2, 4, 5, 7, 8}}};
 
-		std::array<std::uint8_t, 5> inbuf;
-		std::array<std::uint8_t, 8> outbuf;
+		aux::array<std::uint8_t, 5> inbuf;
+		aux::array<std::uint8_t, 8> outbuf;
 
 		std::string ret;
 		for (std::string::const_iterator i = s.begin(); i != s.end();)
@@ -383,8 +384,8 @@ namespace libtorrent
 
 	std::string base32decode(std::string const& s)
 	{
-		std::array<std::uint8_t, 8> inbuf;
-		std::array<std::uint8_t, 5> outbuf;
+		aux::array<std::uint8_t, 8> inbuf;
+		aux::array<std::uint8_t, 5> outbuf;
 
 		std::string ret;
 		for (std::string::const_iterator i = s.begin(); i != s.end();)
@@ -400,9 +401,9 @@ namespace libtorrent
 			{
 				char const in = char(std::toupper(*i++));
 				if (in >= 'A' && in <= 'Z')
-					inbuf[j] = in - 'A';
+					inbuf[j] = (in - 'A') & 0xff;
 				else if (in >= '2' && in <= '7')
-					inbuf[j] = in - '2' + ('Z' - 'A') + 1;
+					inbuf[j] = (in - '2' + ('Z' - 'A') + 1) & 0xff;
 				else if (in == '=')
 				{
 					inbuf[j] = 0;
diff --git a/src/file.cpp b/src/file.cpp
index 499a8845a..9a9f5e0dd 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -429,9 +429,9 @@ namespace libtorrent
 		}
 
 		s->file_size = ret.st_size;
-		s->atime = ret.st_atime;
-		s->mtime = ret.st_mtime;
-		s->ctime = ret.st_ctime;
+		s->atime = std::uint64_t(ret.st_atime);
+		s->mtime = std::uint64_t(ret.st_mtime);
+		s->ctime = std::uint64_t(ret.st_ctime);
 
 		s->mode = (S_ISREG(ret.st_mode) ? file_status::regular_file : 0)
 			| (S_ISDIR(ret.st_mode) ? file_status::directory : 0)
@@ -708,7 +708,7 @@ namespace libtorrent
 				) ++p;
 			if (p - start > 0)
 			{
-				ret.append(start, p - start);
+				ret.append(start, aux::numeric_cast<std::size_t>(p - start));
 				if (only_first_part) return ret;
 				ret.append(1, '\0');
 			}
@@ -731,12 +731,13 @@ namespace libtorrent
 	{
 		for (int i = int(f.size()) - 1; i >= 0; --i)
 		{
-			if (f[i] == '/') break;
+			std::size_t const idx = std::size_t(i);
+			if (f[idx] == '/') break;
 #ifdef TORRENT_WINDOWS
-			if (f[i] == '\\') break;
+			if (f[idx] == '\\') break;
 #endif
-			if (f[i] != '.') continue;
-			return f.substr(i);
+			if (f[idx] != '.') continue;
+			return f.substr(idx);
 		}
 		return "";
 	}
@@ -750,21 +751,22 @@ namespace libtorrent
 		char const* ext = std::strrchr(f.c_str(), '.');
 		// if we don't have an extension, just return f
 		if (ext == nullptr || ext == &f[0] || (slash != nullptr && ext < slash)) return f;
-		return f.substr(0, ext - &f[0]);
+		return f.substr(0, aux::numeric_cast<std::size_t>(ext - &f[0]));
 	}
 
 	void replace_extension(std::string& f, std::string const& ext)
 	{
 		for (int i = int(f.size()) - 1; i >= 0; --i)
 		{
-			if (f[i] == '/') break;
+			std::size_t const idx = std::size_t(i);
+			if (f[idx] == '/') break;
 #ifdef TORRENT_WINDOWS
-			if (f[i] == '\\') break;
+			if (f[idx] == '\\') break;
 #endif
 
-			if (f[i] != '.') continue;
+			if (f[idx] != '.') continue;
 
-			f.resize(i);
+			f.resize(idx);
 			break;
 		}
 		f += '.';
@@ -813,10 +815,10 @@ namespace libtorrent
 
 		int len = int(f.size()) - 1;
 		// if the last character is / or \ ignore it
-		if (f[len] == '/' || f[len] == '\\') --len;
+		if (f[std::size_t(len)] == '/' || f[std::size_t(len)] == '\\') --len;
 		while (len >= 0)
 		{
-			if (f[len] == '/' || f[len] == '\\')
+			if (f[std::size_t(len)] == '/' || f[std::size_t(len)] == '\\')
 				break;
 			--len;
 		}
@@ -835,16 +837,16 @@ namespace libtorrent
 
 		int len = int(f.size());
 		// if the last character is / or \ ignore it
-		if (f[len-1] == '/' || f[len-1] == '\\') --len;
+		if (f[std::size_t(len - 1)] == '/' || f[std::size_t(len - 1)] == '\\') --len;
 		while (len > 0)
 		{
 			--len;
-			if (f[len] == '/' || f[len] == '\\')
+			if (f[std::size_t(len)] == '/' || f[std::size_t(len)] == '\\')
 				break;
 		}
 
-		if (f[len] == '/' || f[len] == '\\') ++len;
-		return std::string(f.c_str(), len);
+		if (f[std::size_t(len)] == '/' || f[std::size_t(len)] == '\\') ++len;
+		return std::string(f.c_str(), std::size_t(len));
 	}
 
 	char const* filename_cstr(char const* f)
@@ -884,10 +886,10 @@ namespace libtorrent
 					|| *sep == '\\'
 #endif
 					)
-					return std::string(sep + 1, len);
+					return std::string(sep + 1, std::size_t(len));
 				++len;
 			}
-			return std::string(first, len);
+			return std::string(first, std::size_t(len));
 
 		}
 		return std::string(sep + 1);
@@ -930,12 +932,12 @@ namespace libtorrent
 		bool const need_sep = lhs[lhs.size() - 1] != '/';
 #endif
 		std::string ret;
-		int target_size = int(lhs.size() + rhs.size() + 2);
+		std::size_t target_size = lhs.size() + rhs.size() + 2;
 		ret.resize(target_size);
-		target_size = std::snprintf(&ret[0], target_size, "%*s%s%*s"
+		target_size = aux::numeric_cast<std::size_t>(std::snprintf(&ret[0], target_size, "%*s%s%*s"
 			, int(lhs.size()), lhs.data()
 			, (need_sep ? TORRENT_SEPARATOR : "")
-			, int(rhs.size()), rhs.data());
+			, int(rhs.size()), rhs.data()));
 		ret.resize(target_size);
 		return ret;
 	}
@@ -1628,7 +1630,7 @@ typedef struct _FILE_ALLOCATED_RANGE_BUFFER {
 	bool coalesce_read_buffers(span<iovec_t const>& bufs
 		, iovec_t& tmp)
 	{
-		int const buf_size = bufs_size(bufs);
+		std::size_t const buf_size = aux::numeric_cast<std::size_t>(bufs_size(bufs));
 		char* buf = static_cast<char*>(std::malloc(buf_size));
 		if (!buf) return false;
 		tmp.iov_base = buf;
@@ -1647,7 +1649,7 @@ typedef struct _FILE_ALLOCATED_RANGE_BUFFER {
 	bool coalesce_write_buffers(span<iovec_t const>& bufs
 		, iovec_t& tmp)
 	{
-		int const buf_size = bufs_size(bufs);
+		std::size_t const buf_size = aux::numeric_cast<std::size_t>(bufs_size(bufs));
 		char* buf = static_cast<char*>(std::malloc(buf_size));
 		if (!buf) return false;
 		gather_copy(bufs, buf);
diff --git a/src/kademlia/dht_storage.cpp b/src/kademlia/dht_storage.cpp
index 92dd48d01..f7571bcbf 100644
--- a/src/kademlia/dht_storage.cpp
+++ b/src/kademlia/dht_storage.cpp
@@ -45,6 +45,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <libtorrent/bloom_filter.hpp>
 #include <libtorrent/session_settings.hpp>
 #include <libtorrent/random.hpp>
+#include <libtorrent/aux_/vector.hpp>
 
 namespace libtorrent {
 namespace dht {
@@ -176,7 +177,7 @@ namespace
 
 	struct infohashes_sample
 	{
-		std::vector<sha1_hash> samples;
+		aux::vector<sha1_hash> samples;
 		time_point created = min_time();
 
 		int count() const { return int(samples.size()); }
@@ -478,7 +479,7 @@ namespace
 
 			refresh_infohashes_sample();
 
-			std::vector<sha1_hash> const& samples = m_infohashes_sample.samples;
+			aux::vector<sha1_hash> const& samples = m_infohashes_sample.samples;
 			item["samples"] = span<char const>(
 				reinterpret_cast<char const*>(samples.data()), samples.size() * 20);
 
@@ -582,7 +583,7 @@ namespace
 				&& m_infohashes_sample.count() >= max_count)
 				return;
 
-			std::vector<sha1_hash>& samples = m_infohashes_sample.samples;
+			aux::vector<sha1_hash>& samples = m_infohashes_sample.samples;
 			samples.clear();
 			samples.reserve(count);
 
diff --git a/src/kademlia/routing_table.cpp b/src/kademlia/routing_table.cpp
index c8cae2abb..0151a25f0 100644
--- a/src/kademlia/routing_table.cpp
+++ b/src/kademlia/routing_table.cpp
@@ -51,6 +51,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/socket_io.hpp" // for print_endpoint
 #include "libtorrent/invariant_check.hpp"
 #include "libtorrent/address.hpp"
+#include "libtorrent/aux_/array.hpp"
 
 using namespace std::placeholders;
 
@@ -126,8 +127,8 @@ int routing_table::bucket_limit(int bucket) const
 {
 	if (!m_settings.extended_routing_table) return m_bucket_size;
 
-	static const int size_exceptions[] = {16, 8, 4, 2};
-	if (bucket < int(sizeof(size_exceptions) / sizeof(size_exceptions[0])))
+	static const aux::array<int, 4> size_exceptions{{{16, 8, 4, 2}}};
+	if (bucket < size_exceptions.end_index())
 		return m_bucket_size * size_exceptions[bucket];
 	return m_bucket_size;
 }
@@ -692,7 +693,7 @@ ip_ok:
 		// the data someone is looking for, make sure there is an affinity
 		// towards having a good spread of node IDs in each bucket
 
-		std::uint32_t mask = bucket_size_limit - 1;
+		int mask = bucket_size_limit - 1;
 		int mask_shift = 0;
 		TORRENT_ASSERT_VAL(mask > 0, mask);
 		while ((mask & 0x80) == 0)
@@ -738,7 +739,7 @@ ip_ok:
 			// have a unique prefix
 
 			// find node entries with duplicate prefixes in O(1)
-			std::vector<bucket_t::iterator> prefix(int(1 << (8 - mask_shift)), b.end());
+			aux::vector<bucket_t::iterator> prefix(aux::numeric_cast<std::size_t>(int(1 << (8 - mask_shift))), b.end());
 			TORRENT_ASSERT(int(prefix.size()) >= bucket_size_limit);
 
 			// the begin iterator from this object is used as a placeholder
@@ -1061,7 +1062,7 @@ void routing_table::find_node(node_id const& target
 	int const bucket_index = int(std::distance(m_buckets.begin(), i));
 	int const bucket_size_limit = bucket_limit(bucket_index);
 
-	l.reserve(bucket_size_limit);
+	l.reserve(aux::numeric_cast<std::size_t>(bucket_size_limit));
 
 	table_t::iterator j = i;
 
@@ -1088,7 +1089,7 @@ void routing_table::find_node(node_id const& target
 				, [&target](node_entry const& lhs, node_entry const& rhs)
 				{ return compare_ref(lhs.id, rhs.id, target); });
 
-			l.resize(count);
+			l.resize(aux::numeric_cast<std::size_t>(count));
 			return;
 		}
 		unsorted_start_idx = int(l.size());
@@ -1127,7 +1128,7 @@ void routing_table::find_node(node_id const& target
 				, [&target](node_entry const& lhs, node_entry const& rhs)
 				{ return compare_ref(lhs.id, rhs.id, target); });
 
-			l.resize(count);
+			l.resize(aux::numeric_cast<std::size_t>(count));
 			return;
 		}
 		unsorted_start_idx = int(l.size());
diff --git a/src/performance_counters.cpp b/src/performance_counters.cpp
index 0cf6dfb9a..1b2a6d01b 100644
--- a/src/performance_counters.cpp
+++ b/src/performance_counters.cpp
@@ -50,7 +50,7 @@ namespace libtorrent {
 	counters::counters(counters const& c)
 	{
 #ifdef ATOMIC_LLONG_LOCK_FREE
-		for (std::size_t i = 0; i < m_stats_counter.size(); ++i)
+		for (int i = 0; i < m_stats_counter.end_index(); ++i)
 			m_stats_counter[i].store(
 				c.m_stats_counter[i].load(std::memory_order_relaxed)
 					, std::memory_order_relaxed);
@@ -63,7 +63,7 @@ namespace libtorrent {
 	counters& counters::operator=(counters const& c)
 	{
 #ifdef ATOMIC_LLONG_LOCK_FREE
-		for (std::size_t i = 0; i < m_stats_counter.size(); ++i)
+		for (int i = 0; i < m_stats_counter.end_index(); ++i)
 			m_stats_counter[i].store(
 				c.m_stats_counter[i].load(std::memory_order_relaxed)
 					, std::memory_order_relaxed);
@@ -90,7 +90,7 @@ namespace libtorrent {
 
 	// the argument specifies which counter to
 	// increment or decrement
-	std::int64_t counters::inc_stats_counter(int c, std::int64_t value)
+	std::int64_t counters::inc_stats_counter(int const c, std::int64_t const value)
 	{
 		// if c >= num_stats_counters, it means it's not
 		// a monotonically increasing counter, but a gauge
@@ -110,9 +110,9 @@ namespace libtorrent {
 #endif
 	}
 
-	// ratio is a vaue between 0 and 100 representing the percentage the value
+	// ratio is a value between 0 and 100 representing the percentage the value
 	// is blended in at.
-	void counters::blend_stats_counter(int c, std::int64_t value, int ratio)
+	void counters::blend_stats_counter(int const c, std::int64_t const value, int const ratio)
 	{
 		TORRENT_ASSERT(c >= num_stats_counters);
 		TORRENT_ASSERT(c < num_counters);
@@ -121,21 +121,21 @@ namespace libtorrent {
 
 #ifdef ATOMIC_LLONG_LOCK_FREE
 		std::int64_t current = m_stats_counter[c].load(std::memory_order_relaxed);
-		std::int64_t new_value = (current * (100-ratio) + value * ratio) / 100;
+		std::int64_t new_value = (current * (100 - ratio) + value * ratio) / 100;
 
 		while (!m_stats_counter[c].compare_exchange_weak(current, new_value
 			, std::memory_order_relaxed))
 		{
-			new_value = (current * (100-ratio) + value * ratio) / 100;
+			new_value = (current * (100 - ratio) + value * ratio) / 100;
 		}
 #else
 		std::lock_guard<std::mutex> l(m_mutex);
 		std::int64_t current = m_stats_counter[c];
-		m_stats_counter[c] = (current * (100-ratio) + value * ratio) / 100;
+		m_stats_counter[c] = (current * (100 - ratio) + value * ratio) / 100;
 #endif
 	}
 
-	void counters::set_value(int c, std::int64_t value)
+	void counters::set_value(int const c, std::int64_t const value)
 	{
 		TORRENT_ASSERT(c >= 0);
 		TORRENT_ASSERT(c < num_counters);
diff --git a/src/settings_pack.cpp b/src/settings_pack.cpp
index fa5b926fe..316617807 100644
--- a/src/settings_pack.cpp
+++ b/src/settings_pack.cpp
@@ -35,9 +35,9 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/assert.hpp"
 #include "libtorrent/settings_pack.hpp"
 #include "libtorrent/aux_/session_impl.hpp"
+#include "libtorrent/aux_/array.hpp"
 
 #include <algorithm>
-#include <array>
 
 namespace {
 
@@ -99,8 +99,8 @@ namespace libtorrent
 
 	using aux::session_impl;
 
-	std::array<str_setting_entry_t, settings_pack::num_string_settings> str_settings =
-	{{
+	aux::array<str_setting_entry_t, settings_pack::num_string_settings> const str_settings
+	({{
 		SET(user_agent, "libtorrent/" LIBTORRENT_VERSION, &session_impl::update_user_agent),
 		SET(announce_ip, nullptr, nullptr),
 		SET(mmap_cache, nullptr, nullptr),
@@ -117,10 +117,10 @@ namespace libtorrent
 		SET(i2p_hostname, "", &session_impl::update_i2p_bridge),
 		SET(peer_fingerprint, "-LT1200-", &session_impl::update_peer_fingerprint),
 		SET(dht_bootstrap_nodes, "dht.libtorrent.org:25401", &session_impl::update_dht_bootstrap_nodes)
-	}};
+	}});
 
-	std::array<bool_setting_entry_t, settings_pack::num_bool_settings> bool_settings =
-	{{
+	aux::array<bool_setting_entry_t, settings_pack::num_bool_settings> const bool_settings
+	({{
 		SET(allow_multiple_connections_per_ip, false, nullptr),
 		DEPRECATED_SET(ignore_limits_on_local_network, true, &session_impl::update_ignore_rate_limits_on_local_network),
 		SET(send_redundant_have, true, nullptr),
@@ -189,10 +189,10 @@ namespace libtorrent
 		SET(proxy_peer_connections, true, nullptr),
 		SET(auto_sequential, true, &session_impl::update_auto_sequential),
 		SET(proxy_tracker_connections, true, nullptr),
-	}};
+	}});
 
-	std::array<int_setting_entry_t, settings_pack::num_int_settings> int_settings =
-	{{
+	aux::array<int_setting_entry_t, settings_pack::num_int_settings> const int_settings
+	({{
 		SET(tracker_completion_timeout, 30, nullptr),
 		SET(tracker_receive_timeout, 10, nullptr),
 		SET(stop_tracker_timeout, 5, nullptr),
@@ -321,7 +321,7 @@ namespace libtorrent
 		SET(proxy_port, 0, &session_impl::update_proxy),
 		SET(i2p_port, 0, &session_impl::update_i2p_bridge),
 		SET(cache_size_volatile, 256, nullptr)
-	}};
+	}});
 
 #undef SET
 #undef SET_DEPRECATED
@@ -330,20 +330,20 @@ namespace libtorrent
 
 	int setting_by_name(std::string const& key)
 	{
-		for (std::size_t k = 0; k < str_settings.size(); ++k)
+		for (int k = 0; k < str_settings.end_index(); ++k)
 		{
 			if (key != str_settings[k].name) continue;
-			return settings_pack::string_type_base + int(k);
+			return settings_pack::string_type_base + k;
 		}
-		for (std::size_t k = 0; k < int_settings.size(); ++k)
+		for (int k = 0; k < int_settings.end_index(); ++k)
 		{
 			if (key != int_settings[k].name) continue;
-			return settings_pack::int_type_base + int(k);
+			return settings_pack::int_type_base + k;
 		}
-		for (std::size_t k = 0; k < bool_settings.size(); ++k)
+		for (int k = 0; k < bool_settings.end_index(); ++k)
 		{
 			if (key != bool_settings[k].name) continue;
-			return settings_pack::bool_type_base + int(k);
+			return settings_pack::bool_type_base + k;
 		}
 		return -1;
 	}
@@ -379,27 +379,27 @@ namespace libtorrent
 				case bdecode_node::int_t:
 				{
 					bool found = false;
-					for (std::size_t k = 0; k < int_settings.size(); ++k)
+					for (int k = 0; k < int_settings.end_index(); ++k)
 					{
 						if (key != int_settings[k].name) continue;
-						pack.set_int(settings_pack::int_type_base + int(k), int(val.int_value()));
+						pack.set_int(settings_pack::int_type_base + k, int(val.int_value()));
 						found = true;
 						break;
 					}
 					if (found) continue;
-					for (std::size_t k = 0; k < bool_settings.size(); ++k)
+					for (int k = 0; k < bool_settings.end_index(); ++k)
 					{
 						if (key != bool_settings[k].name) continue;
-						pack.set_bool(settings_pack::bool_type_base + int(k), val.int_value() != 0);
+						pack.set_bool(settings_pack::bool_type_base + k, val.int_value() != 0);
 						break;
 					}
 				}
 				break;
 			case bdecode_node::string_t:
-				for (std::size_t k = 0; k < str_settings.size(); ++k)
+				for (int k = 0; k < str_settings.end_index(); ++k)
 				{
 					if (key != str_settings[k].name) continue;
-					pack.set_str(settings_pack::string_type_base + int(k), val.string_value().to_string());
+					pack.set_str(settings_pack::string_type_base + k, val.string_value().to_string());
 					break;
 				}
 				break;
@@ -416,20 +416,20 @@ namespace libtorrent
 		for (int i = 0; i < settings_pack::num_string_settings; ++i)
 		{
 			char const* cmp = str_settings[i].default_value == nullptr ? "" : str_settings[i].default_value;
-			if (cmp == s.m_strings[i]) continue;
-			sett[str_settings[i].name] = s.m_strings[i];
+			if (cmp == s.m_strings[std::size_t(i)]) continue;
+			sett[str_settings[i].name] = s.m_strings[std::size_t(i)];
 		}
 
 		for (int i = 0; i < settings_pack::num_int_settings; ++i)
 		{
-			if (int_settings[i].default_value == s.m_ints[i]) continue;
-			sett[int_settings[i].name] = s.m_ints[i];
+			if (int_settings[i].default_value == s.m_ints[std::size_t(i)]) continue;
+			sett[int_settings[i].name] = s.m_ints[std::size_t(i)];
 		}
 
 		for (int i = 0; i < settings_pack::num_bool_settings; ++i)
 		{
-			if (bool_settings[i].default_value == s.m_bools[i]) continue;
-			sett[bool_settings[i].name] = s.m_bools[i];
+			if (bool_settings[i].default_value == s.m_bools[std::size_t(i)]) continue;
+			sett[bool_settings[i].name] = s.m_bools[std::size_t(i)];
 		}
 	}
 
@@ -674,27 +674,24 @@ namespace libtorrent
 			case string_type_base:
 			{
 				std::pair<std::uint16_t, std::string> v(name, std::string());
-				std::vector<std::pair<std::uint16_t, std::string> >::iterator i
-					= std::lower_bound(m_strings.begin(), m_strings.end(), v
-						, &compare_first<std::string>);
+				auto const i = std::lower_bound(m_strings.begin(), m_strings.end()
+					, v, &compare_first<std::string>);
 				if (i != m_strings.end() && i->first == name) m_strings.erase(i);
 				break;
 			}
 			case int_type_base:
 			{
 				std::pair<std::uint16_t, int> v(name, 0);
-				std::vector<std::pair<std::uint16_t, int> >::iterator i
-					= std::lower_bound(m_ints.begin(), m_ints.end(), v
-						, &compare_first<int>);
+				auto const i = std::lower_bound(m_ints.begin(), m_ints.end()
+					, v, &compare_first<int>);
 				if (i != m_ints.end() && i->first == name) m_ints.erase(i);
 				break;
 			}
 			case bool_type_base:
 			{
 				std::pair<std::uint16_t, bool> v(name, false);
-				std::vector<std::pair<std::uint16_t, bool> >::iterator i
-					= std::lower_bound(m_bools.begin(), m_bools.end(), v
-					, &compare_first<bool>);
+				auto const i = std::lower_bound(m_bools.begin(), m_bools.end()
+					, v, &compare_first<bool>);
 				if (i != m_bools.end() && i->first == name) m_bools.erase(i);
 				break;
 			}