diff --git a/libtorrent/include/libtorrent/asio/detail/epoll_reactor.hpp b/libtorrent/include/libtorrent/asio/detail/epoll_reactor.hpp
index 9c406c3fa..e260c5194 100644
--- a/libtorrent/include/libtorrent/asio/detail/epoll_reactor.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/epoll_reactor.hpp
@@ -157,7 +157,8 @@ public:
       int result = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev);
       if (result != 0)
       {
-        asio::error_code ec(errno, asio::native_ecat);
+        asio::error_code ec(errno,
+            asio::error::system_category);
         read_op_queue_.dispatch_all_operations(descriptor, ec);
       }
     }
@@ -190,7 +191,8 @@ public:
       int result = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev);
       if (result != 0)
       {
-        asio::error_code ec(errno, asio::native_ecat);
+        asio::error_code ec(errno,
+            asio::error::system_category);
         write_op_queue_.dispatch_all_operations(descriptor, ec);
       }
     }
@@ -219,7 +221,8 @@ public:
       int result = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev);
       if (result != 0)
       {
-        asio::error_code ec(errno, asio::native_ecat);
+        asio::error_code ec(errno,
+            asio::error::system_category);
         except_op_queue_.dispatch_all_operations(descriptor, ec);
       }
     }
@@ -250,7 +253,8 @@ public:
       int result = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev);
       if (result != 0)
       {
-        asio::error_code ec(errno, asio::native_ecat);
+        asio::error_code ec(errno,
+            asio::error::system_category);
         write_op_queue_.dispatch_all_operations(descriptor, ec);
         except_op_queue_.dispatch_all_operations(descriptor, ec);
       }
@@ -427,7 +431,8 @@ private:
         int result = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev);
         if (result != 0)
         {
-          ec = asio::error_code(errno, asio::native_ecat);
+          ec = asio::error_code(errno,
+              asio::error::system_category);
           read_op_queue_.dispatch_all_operations(descriptor, ec);
           write_op_queue_.dispatch_all_operations(descriptor, ec);
           except_op_queue_.dispatch_all_operations(descriptor, ec);
@@ -485,8 +490,10 @@ private:
     int fd = epoll_create(epoll_size);
     if (fd == -1)
     {
-      boost::throw_exception(asio::system_error(
-            asio::error_code(errno, asio::native_ecat),
+      boost::throw_exception(
+          asio::system_error(
+            asio::error_code(errno,
+              asio::error::system_category),
             "epoll"));
     }
     return fd;
diff --git a/libtorrent/include/libtorrent/asio/detail/kqueue_reactor.hpp b/libtorrent/include/libtorrent/asio/detail/kqueue_reactor.hpp
index 18a842b46..5fffc6788 100644
--- a/libtorrent/include/libtorrent/asio/detail/kqueue_reactor.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/kqueue_reactor.hpp
@@ -150,7 +150,8 @@ public:
       EV_SET(&event, descriptor, EVFILT_READ, EV_ADD, 0, 0, 0);
       if (::kevent(kqueue_fd_, &event, 1, 0, 0, 0) == -1)
       {
-        asio::error_code ec(errno, asio::native_ecat);
+        asio::error_code ec(errno,
+            asio::error::system_category);
         read_op_queue_.dispatch_all_operations(descriptor, ec);
       }
     }
@@ -176,7 +177,8 @@ public:
       EV_SET(&event, descriptor, EVFILT_WRITE, EV_ADD, 0, 0, 0);
       if (::kevent(kqueue_fd_, &event, 1, 0, 0, 0) == -1)
       {
-        asio::error_code ec(errno, asio::native_ecat);
+        asio::error_code ec(errno,
+            asio::error::system_category);
         write_op_queue_.dispatch_all_operations(descriptor, ec);
       }
     }
@@ -201,7 +203,8 @@ public:
         EV_SET(&event, descriptor, EVFILT_READ, EV_ADD, EV_OOBAND, 0, 0);
       if (::kevent(kqueue_fd_, &event, 1, 0, 0, 0) == -1)
       {
-        asio::error_code ec(errno, asio::native_ecat);
+        asio::error_code ec(errno,
+            asio::error::system_category);
         except_op_queue_.dispatch_all_operations(descriptor, ec);
       }
     }
@@ -224,7 +227,8 @@ public:
       EV_SET(&event, descriptor, EVFILT_WRITE, EV_ADD, 0, 0, 0);
       if (::kevent(kqueue_fd_, &event, 1, 0, 0, 0) == -1)
       {
-        asio::error_code ec(errno, asio::native_ecat);
+        asio::error_code ec(errno,
+            asio::error::system_category);
         write_op_queue_.dispatch_all_operations(descriptor, ec);
       }
     }
@@ -238,7 +242,8 @@ public:
         EV_SET(&event, descriptor, EVFILT_READ, EV_ADD, EV_OOBAND, 0, 0);
       if (::kevent(kqueue_fd_, &event, 1, 0, 0, 0) == -1)
       {
-        asio::error_code ec(errno, asio::native_ecat);
+        asio::error_code ec(errno,
+            asio::error::system_category);
         except_op_queue_.dispatch_all_operations(descriptor, ec);
         write_op_queue_.dispatch_all_operations(descriptor, ec);
       }
@@ -392,7 +397,7 @@ private:
         if (events[i].flags & EV_ERROR)
         {
           asio::error_code error(
-              events[i].data, asio::native_ecat);
+              events[i].data, asio::error::system_category);
           except_op_queue_.dispatch_all_operations(descriptor, error);
           read_op_queue_.dispatch_all_operations(descriptor, error);
         }
@@ -422,7 +427,8 @@ private:
           EV_SET(&event, descriptor, EVFILT_READ, EV_DELETE, 0, 0, 0);
         if (::kevent(kqueue_fd_, &event, 1, 0, 0, 0) == -1)
         {
-          asio::error_code error(errno, asio::native_ecat);
+          asio::error_code error(errno,
+              asio::error::system_category);
           except_op_queue_.dispatch_all_operations(descriptor, error);
           read_op_queue_.dispatch_all_operations(descriptor, error);
         }
@@ -434,7 +440,7 @@ private:
         if (events[i].flags & EV_ERROR)
         {
           asio::error_code error(
-              events[i].data, asio::native_ecat);
+              events[i].data, asio::error::system_category);
           write_op_queue_.dispatch_all_operations(descriptor, error);
         }
         else
@@ -451,7 +457,8 @@ private:
           EV_SET(&event, descriptor, EVFILT_WRITE, EV_DELETE, 0, 0, 0);
         if (::kevent(kqueue_fd_, &event, 1, 0, 0, 0) == -1)
         {
-          asio::error_code error(errno, asio::native_ecat);
+          asio::error_code error(errno,
+              asio::error::system_category);
           write_op_queue_.dispatch_all_operations(descriptor, error);
         }
       }
@@ -505,8 +512,10 @@ private:
     int fd = kqueue();
     if (fd == -1)
     {
-      boost::throw_exception(asio::system_error(
-            asio::error_code(errno, asio::native_ecat),
+      boost::throw_exception(
+          asio::system_error(
+            asio::error_code(errno,
+              asio::error::system_category),
             "kqueue"));
     }
     return fd;
diff --git a/libtorrent/include/libtorrent/asio/detail/posix_event.hpp b/libtorrent/include/libtorrent/asio/detail/posix_event.hpp
index 1197ac3f1..b48586f15 100644
--- a/libtorrent/include/libtorrent/asio/detail/posix_event.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/posix_event.hpp
@@ -29,6 +29,7 @@
 #include <pthread.h>
 #include "asio/detail/pop_options.hpp"
 
+#include "asio/error.hpp"
 #include "asio/system_error.hpp"
 #include "asio/detail/noncopyable.hpp"
 
@@ -47,7 +48,7 @@ public:
     if (error != 0)
     {
       asio::system_error e(
-          asio::error_code(error, asio::native_ecat),
+          asio::error_code(error, asio::error::system_category),
           "event");
       boost::throw_exception(e);
     }
diff --git a/libtorrent/include/libtorrent/asio/detail/posix_mutex.hpp b/libtorrent/include/libtorrent/asio/detail/posix_mutex.hpp
index 224722bb4..6067880fb 100644
--- a/libtorrent/include/libtorrent/asio/detail/posix_mutex.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/posix_mutex.hpp
@@ -28,6 +28,7 @@
 #include <pthread.h>
 #include "asio/detail/pop_options.hpp"
 
+#include "asio/error.hpp"
 #include "asio/system_error.hpp"
 #include "asio/detail/noncopyable.hpp"
 #include "asio/detail/scoped_lock.hpp"
@@ -50,7 +51,7 @@ public:
     if (error != 0)
     {
       asio::system_error e(
-          asio::error_code(error, asio::native_ecat),
+          asio::error_code(error, asio::error::system_category),
           "mutex");
       boost::throw_exception(e);
     }
@@ -69,7 +70,7 @@ public:
     if (error != 0)
     {
       asio::system_error e(
-          asio::error_code(error, asio::native_ecat),
+          asio::error_code(error, asio::error::system_category),
           "mutex");
       boost::throw_exception(e);
     }
@@ -82,7 +83,7 @@ public:
     if (error != 0)
     {
       asio::system_error e(
-          asio::error_code(error, asio::native_ecat),
+          asio::error_code(error, asio::error::system_category),
           "mutex");
       boost::throw_exception(e);
     }
diff --git a/libtorrent/include/libtorrent/asio/detail/posix_thread.hpp b/libtorrent/include/libtorrent/asio/detail/posix_thread.hpp
index f01b40428..6e5815426 100644
--- a/libtorrent/include/libtorrent/asio/detail/posix_thread.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/posix_thread.hpp
@@ -29,6 +29,7 @@
 #include <pthread.h>
 #include "asio/detail/pop_options.hpp"
 
+#include "asio/error.hpp"
 #include "asio/system_error.hpp"
 #include "asio/detail/noncopyable.hpp"
 
@@ -52,7 +53,7 @@ public:
     if (error != 0)
     {
       asio::system_error e(
-          asio::error_code(error, asio::native_ecat),
+          asio::error_code(error, asio::error::system_category),
           "thread");
       boost::throw_exception(e);
     }
diff --git a/libtorrent/include/libtorrent/asio/detail/posix_tss_ptr.hpp b/libtorrent/include/libtorrent/asio/detail/posix_tss_ptr.hpp
index 93fce3479..dda329c40 100644
--- a/libtorrent/include/libtorrent/asio/detail/posix_tss_ptr.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/posix_tss_ptr.hpp
@@ -28,6 +28,7 @@
 #include <pthread.h>
 #include "asio/detail/pop_options.hpp"
 
+#include "asio/error.hpp"
 #include "asio/system_error.hpp"
 #include "asio/detail/noncopyable.hpp"
 
@@ -46,7 +47,7 @@ public:
     if (error != 0)
     {
       asio::system_error e(
-          asio::error_code(error, asio::native_ecat),
+          asio::error_code(error, asio::error::system_category),
           "tss");
       boost::throw_exception(e);
     }
diff --git a/libtorrent/include/libtorrent/asio/detail/reactive_socket_service.hpp b/libtorrent/include/libtorrent/asio/detail/reactive_socket_service.hpp
index e4b4dfa7c..9c0075821 100644
--- a/libtorrent/include/libtorrent/asio/detail/reactive_socket_service.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/reactive_socket_service.hpp
@@ -157,7 +157,7 @@ public:
 
     if (int err = reactor_.register_descriptor(sock.get()))
     {
-      ec = asio::error_code(err, asio::native_ecat);
+      ec = asio::error_code(err, asio::error::system_category);
       return ec;
     }
 
@@ -181,7 +181,7 @@ public:
 
     if (int err = reactor_.register_descriptor(native_socket))
     {
-      ec = asio::error_code(err, asio::native_ecat);
+      ec = asio::error_code(err, asio::error::system_category);
       return ec;
     }
 
@@ -1124,7 +1124,7 @@ public:
     bool operator()(const asio::error_code& result)
     {
       // Check whether the operation was successful.
-      if (result != 0)
+      if (result)
       {
         io_service_.post(bind_handler(handler_, result, 0));
         return true;
@@ -1489,7 +1489,7 @@ public:
       if (connect_error)
       {
         ec = asio::error_code(connect_error,
-            asio::native_ecat);
+            asio::error::system_category);
         io_service_.post(bind_handler(handler_, ec));
         return true;
       }
diff --git a/libtorrent/include/libtorrent/asio/detail/socket_ops.hpp b/libtorrent/include/libtorrent/asio/detail/socket_ops.hpp
index 7f4e15edf..98f3b0f64 100644
--- a/libtorrent/include/libtorrent/asio/detail/socket_ops.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/socket_ops.hpp
@@ -52,9 +52,10 @@ inline ReturnType error_wrapper(ReturnType return_value,
     asio::error_code& ec)
 {
 #if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
-  ec = asio::error_code(WSAGetLastError(), asio::native_ecat);
+  ec = asio::error_code(WSAGetLastError(),
+      asio::error::system_category);
 #else
-  ec = asio::error_code(errno, asio::native_ecat);
+  ec = asio::error_code(errno, asio::error::system_category);
 #endif
   return return_value;
 }
@@ -923,6 +924,13 @@ inline void gai_free(void* p)
   ::operator delete(p);
 }
 
+inline void gai_strcpy(char* target, const char* source, std::size_t max_size)
+{
+  using namespace std;
+  *target = 0;
+  strncat(target, source, max_size);
+}
+
 enum { gai_clone_flag = 1 << 30 };
 
 inline int gai_aistruct(addrinfo_type*** next, const addrinfo_type* hints,
@@ -1292,14 +1300,15 @@ inline int getaddrinfo_emulation(const char* host, const char* service,
     if (host != 0 && host[0] != '\0' && hptr->h_name && hptr->h_name[0]
         && (hints.ai_flags & AI_CANONNAME) && canon == 0)
     {
-      canon = gai_alloc<char>(strlen(hptr->h_name) + 1);
+      std::size_t canon_len = strlen(hptr->h_name) + 1;
+      canon = gai_alloc<char>(canon_len);
       if (canon == 0)
       {
         freeaddrinfo_emulation(aihead);
         socket_ops::freehostent(hptr);
         return EAI_MEMORY;
       }
-      strcpy(canon, hptr->h_name);
+      gai_strcpy(canon, hptr->h_name, canon_len);
     }
 
     // Create an addrinfo structure for each returned address.
@@ -1335,13 +1344,14 @@ inline int getaddrinfo_emulation(const char* host, const char* service,
     }
     else
     {
-      aihead->ai_canonname = gai_alloc<char>(strlen(search[0].host) + 1);
+      std::size_t canonname_len = strlen(search[0].host) + 1;
+      aihead->ai_canonname = gai_alloc<char>(canonname_len);
       if (aihead->ai_canonname == 0)
       {
         freeaddrinfo_emulation(aihead);
         return EAI_MEMORY;
       }
-      strcpy(aihead->ai_canonname, search[0].host);
+      gai_strcpy(aihead->ai_canonname, search[0].host, canonname_len);
     }
   }
   gai_free(canon);
@@ -1424,8 +1434,7 @@ inline asio::error_code getnameinfo_emulation(
             *dot = 0;
           }
         }
-        *host = '\0';
-        strncat(host, hptr->h_name, hostlen);
+        gai_strcpy(host, hptr->h_name, hostlen);
         socket_ops::freehostent(hptr);
       }
       else
@@ -1463,8 +1472,7 @@ inline asio::error_code getnameinfo_emulation(
       servent* sptr = ::getservbyport(port, (flags & NI_DGRAM) ? "udp" : 0);
       if (sptr && sptr->s_name && sptr->s_name[0] != '\0')
       {
-        *serv = '\0';
-        strncat(serv, sptr->s_name, servlen);
+        gai_strcpy(serv, sptr->s_name, servlen);
       }
       else
       {
@@ -1518,10 +1526,10 @@ inline asio::error_code translate_addrinfo_error(int error)
   default: // Possibly the non-portable EAI_SYSTEM.
 #if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
     return asio::error_code(
-        WSAGetLastError(), asio::native_ecat);
+        WSAGetLastError(), asio::error::system_category);
 #else
     return asio::error_code(
-        errno, asio::native_ecat);
+        errno, asio::error::system_category);
 #endif
   }
 }
diff --git a/libtorrent/include/libtorrent/asio/detail/win_event.hpp b/libtorrent/include/libtorrent/asio/detail/win_event.hpp
index 68f55ff13..c73ed56ea 100644
--- a/libtorrent/include/libtorrent/asio/detail/win_event.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/win_event.hpp
@@ -23,6 +23,7 @@
 
 #if defined(BOOST_WINDOWS)
 
+#include "asio/error.hpp"
 #include "asio/system_error.hpp"
 #include "asio/detail/noncopyable.hpp"
 #include "asio/detail/socket_types.hpp"
@@ -47,7 +48,8 @@ public:
     {
       DWORD last_error = ::GetLastError();
       asio::system_error e(
-          asio::error_code(last_error, asio::native_ecat),
+          asio::error_code(last_error,
+            asio::error::system_category),
           "event");
       boost::throw_exception(e);
     }
diff --git a/libtorrent/include/libtorrent/asio/detail/win_iocp_io_service.hpp b/libtorrent/include/libtorrent/asio/detail/win_iocp_io_service.hpp
index 4957fb01a..61eeb1745 100644
--- a/libtorrent/include/libtorrent/asio/detail/win_iocp_io_service.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/win_iocp_io_service.hpp
@@ -63,7 +63,8 @@ public:
     {
       DWORD last_error = ::GetLastError();
       asio::system_error e(
-          asio::error_code(last_error, asio::native_ecat),
+          asio::error_code(last_error,
+            asio::error::system_category),
           "iocp");
       boost::throw_exception(e);
     }
@@ -173,7 +174,8 @@ public:
       {
         DWORD last_error = ::GetLastError();
         asio::system_error e(
-            asio::error_code(last_error, asio::native_ecat),
+            asio::error_code(last_error,
+              asio::error::system_category),
             "pqcs");
         boost::throw_exception(e);
       }
@@ -228,7 +230,8 @@ public:
     {
       DWORD last_error = ::GetLastError();
       asio::system_error e(
-          asio::error_code(last_error, asio::native_ecat),
+          asio::error_code(last_error,
+            asio::error::system_category),
           "pqcs");
       boost::throw_exception(e);
     }
@@ -247,7 +250,8 @@ public:
     {
       DWORD last_error = ::GetLastError();
       asio::system_error e(
-          asio::error_code(last_error, asio::native_ecat),
+          asio::error_code(last_error,
+            asio::error::system_category),
           "pqcs");
       boost::throw_exception(e);
     }
@@ -312,7 +316,7 @@ private:
           {
             DWORD last_error = ::GetLastError();
             ec = asio::error_code(last_error,
-                asio::native_ecat);
+                asio::error::system_category);
             return 0;
           }
 
diff --git a/libtorrent/include/libtorrent/asio/detail/win_iocp_socket_service.hpp b/libtorrent/include/libtorrent/asio/detail/win_iocp_socket_service.hpp
index dcef56576..17d1d5887 100644
--- a/libtorrent/include/libtorrent/asio/detail/win_iocp_socket_service.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/win_iocp_socket_service.hpp
@@ -337,7 +337,8 @@ public:
       if (!cancel_io_ex(sock_as_handle, 0))
       {
         DWORD last_error = ::GetLastError();
-        ec = asio::error_code(last_error, asio::native_ecat);
+        ec = asio::error_code(last_error,
+            asio::error::system_category);
       }
       else
       {
@@ -358,7 +359,8 @@ public:
       if (!::CancelIo(sock_as_handle))
       {
         DWORD last_error = ::GetLastError();
-        ec = asio::error_code(last_error, asio::native_ecat);
+        ec = asio::error_code(last_error,
+            asio::error::system_category);
       }
       else
       {
@@ -664,7 +666,8 @@ public:
         last_error = WSAECONNRESET;
       else if (last_error == ERROR_PORT_UNREACHABLE)
         last_error = WSAECONNREFUSED;
-      ec = asio::error_code(last_error, asio::native_ecat);
+      ec = asio::error_code(last_error,
+          asio::error::system_category);
       return 0;
     }
 
@@ -715,7 +718,8 @@ public:
 #endif // defined(ASIO_ENABLE_BUFFER_DEBUGGING)
 
       // Map non-portable errors to their portable counterparts.
-      asio::error_code ec(last_error, asio::native_ecat);
+      asio::error_code ec(last_error,
+          asio::error::system_category);
       if (ec.value() == ERROR_NETNAME_DELETED)
       {
         if (handler_op->cancel_token_.expired())
@@ -817,7 +821,8 @@ public:
     {
       asio::io_service::work work(this->io_service());
       ptr.reset();
-      asio::error_code ec(last_error, asio::native_ecat);
+      asio::error_code ec(last_error,
+          asio::error::system_category);
       iocp_service_.post(bind_handler(handler, ec, bytes_transferred));
     }
     else
@@ -861,7 +866,8 @@ public:
       DWORD last_error = ::WSAGetLastError();
       if (last_error == ERROR_PORT_UNREACHABLE)
         last_error = WSAECONNREFUSED;
-      ec = asio::error_code(last_error, asio::native_ecat);
+      ec = asio::error_code(last_error,
+          asio::error::system_category);
       return 0;
     }
 
@@ -910,7 +916,8 @@ public:
 #endif // defined(ASIO_ENABLE_BUFFER_DEBUGGING)
 
       // Map non-portable errors to their portable counterparts.
-      asio::error_code ec(last_error, asio::native_ecat);
+      asio::error_code ec(last_error,
+          asio::error::system_category);
       if (ec.value() == ERROR_PORT_UNREACHABLE)
       {
         ec = asio::error::connection_refused;
@@ -993,7 +1000,8 @@ public:
     {
       asio::io_service::work work(this->io_service());
       ptr.reset();
-      asio::error_code ec(last_error, asio::native_ecat);
+      asio::error_code ec(last_error,
+          asio::error::system_category);
       iocp_service_.post(bind_handler(handler, ec, bytes_transferred));
     }
     else
@@ -1047,7 +1055,8 @@ public:
         last_error = WSAECONNRESET;
       else if (last_error == ERROR_PORT_UNREACHABLE)
         last_error = WSAECONNREFUSED;
-      ec = asio::error_code(last_error, asio::native_ecat);
+      ec = asio::error_code(last_error,
+          asio::error::system_category);
       return 0;
     }
     if (bytes_transferred == 0)
@@ -1105,7 +1114,8 @@ public:
 #endif // defined(ASIO_ENABLE_BUFFER_DEBUGGING)
 
       // Map non-portable errors to their portable counterparts.
-      asio::error_code ec(last_error, asio::native_ecat);
+      asio::error_code ec(last_error,
+          asio::error::system_category);
       if (ec.value() == ERROR_NETNAME_DELETED)
       {
         if (handler_op->cancel_token_.expired())
@@ -1212,7 +1222,8 @@ public:
     {
       asio::io_service::work work(this->io_service());
       ptr.reset();
-      asio::error_code ec(last_error, asio::native_ecat);
+      asio::error_code ec(last_error,
+          asio::error::system_category);
       iocp_service_.post(bind_handler(handler, ec, bytes_transferred));
     }
     else
@@ -1258,7 +1269,8 @@ public:
       DWORD last_error = ::WSAGetLastError();
       if (last_error == ERROR_PORT_UNREACHABLE)
         last_error = WSAECONNREFUSED;
-      ec = asio::error_code(last_error, asio::native_ecat);
+      ec = asio::error_code(last_error,
+          asio::error::system_category);
       return 0;
     }
     if (bytes_transferred == 0)
@@ -1324,7 +1336,8 @@ public:
 #endif // defined(ASIO_ENABLE_BUFFER_DEBUGGING)
 
       // Map non-portable errors to their portable counterparts.
-      asio::error_code ec(last_error, asio::native_ecat);
+      asio::error_code ec(last_error,
+          asio::error::system_category);
       if (ec.value() == ERROR_PORT_UNREACHABLE)
       {
         ec = asio::error::connection_refused;
@@ -1418,7 +1431,8 @@ public:
     {
       asio::io_service::work work(this->io_service());
       ptr.reset();
-      asio::error_code ec(last_error, asio::native_ecat);
+      asio::error_code ec(last_error,
+          asio::error::system_category);
       iocp_service_.post(bind_handler(handler, ec, bytes_transferred));
     }
     else
@@ -1655,7 +1669,8 @@ public:
       ptr.reset();
 
       // Call the handler.
-      asio::error_code ec(last_error, asio::native_ecat);
+      asio::error_code ec(last_error,
+          asio::error::system_category);
       asio_handler_invoke_helpers::invoke(
           detail::bind_handler(handler, ec), &handler);
     }
@@ -1755,7 +1770,8 @@ public:
       {
         asio::io_service::work work(this->io_service());
         ptr.reset();
-        asio::error_code ec(last_error, asio::native_ecat);
+        asio::error_code ec(last_error,
+            asio::error::system_category);
         iocp_service_.post(bind_handler(handler, ec));
       }
     }
@@ -1831,8 +1847,8 @@ public:
       // If connection failed then post the handler with the error code.
       if (connect_error)
       {
-        ec = asio::error_code(
-            connect_error, asio::native_ecat);
+        ec = asio::error_code(connect_error,
+            asio::error::system_category);
         io_service_.post(bind_handler(handler_, ec));
         return true;
       }
diff --git a/libtorrent/include/libtorrent/asio/detail/win_mutex.hpp b/libtorrent/include/libtorrent/asio/detail/win_mutex.hpp
index 82659831f..4d1bc20c2 100644
--- a/libtorrent/include/libtorrent/asio/detail/win_mutex.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/win_mutex.hpp
@@ -23,6 +23,7 @@
 
 #if defined(BOOST_WINDOWS)
 
+#include "asio/error.hpp"
 #include "asio/system_error.hpp"
 #include "asio/detail/noncopyable.hpp"
 #include "asio/detail/socket_types.hpp"
@@ -48,7 +49,7 @@ public:
     if (error != 0)
     {
       asio::system_error e(
-          asio::error_code(error, asio::native_ecat),
+          asio::error_code(error, asio::error::system_category),
           "mutex");
       boost::throw_exception(e);
     }
@@ -67,7 +68,7 @@ public:
     if (error != 0)
     {
       asio::system_error e(
-          asio::error_code(error, asio::native_ecat),
+          asio::error_code(error, asio::error::system_category),
           "mutex");
       boost::throw_exception(e);
     }
diff --git a/libtorrent/include/libtorrent/asio/detail/win_thread.hpp b/libtorrent/include/libtorrent/asio/detail/win_thread.hpp
index a6c9b15d2..c6bd61af5 100644
--- a/libtorrent/include/libtorrent/asio/detail/win_thread.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/win_thread.hpp
@@ -23,6 +23,7 @@
 
 #if defined(BOOST_WINDOWS)
 
+#include "asio/error.hpp"
 #include "asio/system_error.hpp"
 #include "asio/detail/noncopyable.hpp"
 #include "asio/detail/socket_types.hpp"
@@ -54,7 +55,8 @@ public:
     {
       DWORD last_error = ::GetLastError();
       asio::system_error e(
-          asio::error_code(last_error, asio::native_ecat),
+          asio::error_code(last_error,
+            asio::error::system_category),
           "thread");
       boost::throw_exception(e);
     }
diff --git a/libtorrent/include/libtorrent/asio/detail/win_tss_ptr.hpp b/libtorrent/include/libtorrent/asio/detail/win_tss_ptr.hpp
index d3e2f8161..d84810d41 100644
--- a/libtorrent/include/libtorrent/asio/detail/win_tss_ptr.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/win_tss_ptr.hpp
@@ -23,6 +23,7 @@
 
 #if defined(BOOST_WINDOWS)
 
+#include "asio/error.hpp"
 #include "asio/system_error.hpp"
 #include "asio/detail/noncopyable.hpp"
 #include "asio/detail/socket_types.hpp"
@@ -47,7 +48,8 @@ public:
     {
       DWORD last_error = ::GetLastError();
       asio::system_error e(
-          asio::error_code(last_error, asio::native_ecat),
+          asio::error_code(last_error,
+            asio::error::system_category),
           "tss");
       boost::throw_exception(e);
     }
diff --git a/libtorrent/include/libtorrent/asio/detail/winsock_init.hpp b/libtorrent/include/libtorrent/asio/detail/winsock_init.hpp
index 67c69e8ce..874d2b77b 100644
--- a/libtorrent/include/libtorrent/asio/detail/winsock_init.hpp
+++ b/libtorrent/include/libtorrent/asio/detail/winsock_init.hpp
@@ -85,7 +85,8 @@ public:
     if (this != &instance_ && ref_->result() != 0)
     {
       asio::system_error e(
-          asio::error_code(ref_->result(), asio::native_ecat),
+          asio::error_code(ref_->result(),
+            asio::error::system_category),
           "winsock");
       boost::throw_exception(e);
     }
diff --git a/libtorrent/include/libtorrent/asio/error.hpp b/libtorrent/include/libtorrent/asio/error.hpp
index 935cc6796..a8316be2c 100644
--- a/libtorrent/include/libtorrent/asio/error.hpp
+++ b/libtorrent/include/libtorrent/asio/error.hpp
@@ -37,327 +37,195 @@
 /// INTERNAL ONLY.
 # define ASIO_WIN_OR_POSIX(e_win, e_posix) implementation_defined
 #elif defined(BOOST_WINDOWS) || defined(__CYGWIN__)
-# define ASIO_NATIVE_ERROR(e) \
-    asio::error_code(e, \
-        asio::native_ecat)
-# define ASIO_SOCKET_ERROR(e) \
-    asio::error_code(WSA ## e, \
-        asio::native_ecat)
-# define ASIO_NETDB_ERROR(e) \
-    asio::error_code(WSA ## e, \
-        asio::native_ecat)
-# define ASIO_GETADDRINFO_ERROR(e) \
-    asio::error_code(WSA ## e, \
-        asio::native_ecat)
-# define ASIO_MISC_ERROR(e) \
-    asio::error_code(e, \
-        asio::misc_ecat)
+# define ASIO_NATIVE_ERROR(e) e
+# define ASIO_SOCKET_ERROR(e) WSA ## e
+# define ASIO_NETDB_ERROR(e) WSA ## e
+# define ASIO_GETADDRINFO_ERROR(e) WSA ## e
 # define ASIO_WIN_OR_POSIX(e_win, e_posix) e_win
 #else
-# define ASIO_NATIVE_ERROR(e) \
-    asio::error_code(e, \
-        asio::native_ecat)
-# define ASIO_SOCKET_ERROR(e) \
-    asio::error_code(e, \
-        asio::native_ecat)
-# define ASIO_NETDB_ERROR(e) \
-    asio::error_code(e, \
-        asio::netdb_ecat)
-# define ASIO_GETADDRINFO_ERROR(e) \
-    asio::error_code(e, \
-        asio::addrinfo_ecat)
-# define ASIO_MISC_ERROR(e) \
-    asio::error_code(e, \
-        asio::misc_ecat)
+# define ASIO_NATIVE_ERROR(e) e
+# define ASIO_SOCKET_ERROR(e) e
+# define ASIO_NETDB_ERROR(e) e
+# define ASIO_GETADDRINFO_ERROR(e) e
 # define ASIO_WIN_OR_POSIX(e_win, e_posix) e_posix
 #endif
 
 namespace asio {
+namespace error {
 
-namespace detail {
-
-/// Hack to keep asio library header-file-only.
-template <typename T>
-class error_base
+enum basic_errors
 {
-public:
-  // boostify: error category declarations go here.
-
   /// Permission denied.
-  static const asio::error_code access_denied;
+  access_denied = ASIO_SOCKET_ERROR(EACCES),
 
   /// Address family not supported by protocol.
-  static const asio::error_code address_family_not_supported;
+  address_family_not_supported = ASIO_SOCKET_ERROR(EAFNOSUPPORT),
 
   /// Address already in use.
-  static const asio::error_code address_in_use;
+  address_in_use = ASIO_SOCKET_ERROR(EADDRINUSE),
 
   /// Transport endpoint is already connected.
-  static const asio::error_code already_connected;
-
-  /// Already open.
-  static const asio::error_code already_open;
+  already_connected = ASIO_SOCKET_ERROR(EISCONN),
 
   /// Operation already in progress.
-  static const asio::error_code already_started;
+  already_started = ASIO_SOCKET_ERROR(EALREADY),
 
   /// A connection has been aborted.
-  static const asio::error_code connection_aborted;
+  connection_aborted = ASIO_SOCKET_ERROR(ECONNABORTED),
 
   /// Connection refused.
-  static const asio::error_code connection_refused;
+  connection_refused = ASIO_SOCKET_ERROR(ECONNREFUSED),
 
   /// Connection reset by peer.
-  static const asio::error_code connection_reset;
+  connection_reset = ASIO_SOCKET_ERROR(ECONNRESET),
 
   /// Bad file descriptor.
-  static const asio::error_code bad_descriptor;
-
-  /// End of file or stream.
-  static const asio::error_code eof;
+  bad_descriptor = ASIO_SOCKET_ERROR(EBADF),
 
   /// Bad address.
-  static const asio::error_code fault;
-
-  /// Host not found (authoritative).
-  static const asio::error_code host_not_found;
-
-  /// Host not found (non-authoritative).
-  static const asio::error_code host_not_found_try_again;
+  fault = ASIO_SOCKET_ERROR(EFAULT),
 
   /// No route to host.
-  static const asio::error_code host_unreachable;
+  host_unreachable = ASIO_SOCKET_ERROR(EHOSTUNREACH),
 
   /// Operation now in progress.
-  static const asio::error_code in_progress;
+  in_progress = ASIO_SOCKET_ERROR(EINPROGRESS),
 
   /// Interrupted system call.
-  static const asio::error_code interrupted;
+  interrupted = ASIO_SOCKET_ERROR(EINTR),
 
   /// Invalid argument.
-  static const asio::error_code invalid_argument;
+  invalid_argument = ASIO_SOCKET_ERROR(EINVAL),
 
   /// Message too long.
-  static const asio::error_code message_size;
+  message_size = ASIO_SOCKET_ERROR(EMSGSIZE),
 
   /// Network is down.
-  static const asio::error_code network_down;
+  network_down = ASIO_SOCKET_ERROR(ENETDOWN),
 
   /// Network dropped connection on reset.
-  static const asio::error_code network_reset;
+  network_reset = ASIO_SOCKET_ERROR(ENETRESET),
 
   /// Network is unreachable.
-  static const asio::error_code network_unreachable;
+  network_unreachable = ASIO_SOCKET_ERROR(ENETUNREACH),
 
   /// Too many open files.
-  static const asio::error_code no_descriptors;
+  no_descriptors = ASIO_SOCKET_ERROR(EMFILE),
 
   /// No buffer space available.
-  static const asio::error_code no_buffer_space;
-
-  /// The query is valid but does not have associated address data.
-  static const asio::error_code no_data;
+  no_buffer_space = ASIO_SOCKET_ERROR(ENOBUFS),
 
   /// Cannot allocate memory.
-  static const asio::error_code no_memory;
+  no_memory = ASIO_WIN_OR_POSIX(
+      ASIO_NATIVE_ERROR(ERROR_OUTOFMEMORY),
+      ASIO_NATIVE_ERROR(ENOMEM)),
 
   /// Operation not permitted.
-  static const asio::error_code no_permission;
+  no_permission = ASIO_WIN_OR_POSIX(
+      ASIO_NATIVE_ERROR(ERROR_ACCESS_DENIED),
+      ASIO_NATIVE_ERROR(EPERM)),
 
   /// Protocol not available.
-  static const asio::error_code no_protocol_option;
-
-  /// A non-recoverable error occurred.
-  static const asio::error_code no_recovery;
+  no_protocol_option = ASIO_SOCKET_ERROR(ENOPROTOOPT),
 
   /// Transport endpoint is not connected.
-  static const asio::error_code not_connected;
-
-  /// Element not found.
-  static const asio::error_code not_found;
+  not_connected = ASIO_SOCKET_ERROR(ENOTCONN),
 
   /// Socket operation on non-socket.
-  static const asio::error_code not_socket;
+  not_socket = ASIO_SOCKET_ERROR(ENOTSOCK),
 
   /// Operation cancelled.
-  static const asio::error_code operation_aborted;
+  operation_aborted = ASIO_WIN_OR_POSIX(
+      ASIO_NATIVE_ERROR(ERROR_OPERATION_ABORTED),
+      ASIO_NATIVE_ERROR(ECANCELED)),
 
   /// Operation not supported.
-  static const asio::error_code operation_not_supported;
-
-  /// The service is not supported for the given socket type.
-  static const asio::error_code service_not_found;
-
-  /// The socket type is not supported.
-  static const asio::error_code socket_type_not_supported;
+  operation_not_supported = ASIO_SOCKET_ERROR(EOPNOTSUPP),
 
   /// Cannot send after transport endpoint shutdown.
-  static const asio::error_code shut_down;
+  shut_down = ASIO_SOCKET_ERROR(ESHUTDOWN),
 
   /// Connection timed out.
-  static const asio::error_code timed_out;
+  timed_out = ASIO_SOCKET_ERROR(ETIMEDOUT),
 
   /// Resource temporarily unavailable.
-  static const asio::error_code try_again;
+  try_again = ASIO_WIN_OR_POSIX(
+      ASIO_NATIVE_ERROR(ERROR_RETRY),
+      ASIO_NATIVE_ERROR(EAGAIN)),
 
   /// The socket is marked non-blocking and the requested operation would block.
-  static const asio::error_code would_block;
+  would_block = ASIO_SOCKET_ERROR(EWOULDBLOCK)
+};
 
-private:
-  error_base();
+enum netdb_errors
+{
+  /// Host not found (authoritative).
+  host_not_found = ASIO_NETDB_ERROR(HOST_NOT_FOUND),
+
+  /// Host not found (non-authoritative).
+  host_not_found_try_again = ASIO_NETDB_ERROR(TRY_AGAIN),
+
+  /// The query is valid but does not have associated address data.
+  no_data = ASIO_NETDB_ERROR(NO_DATA),
+
+  /// A non-recoverable error occurred.
+  no_recovery = ASIO_NETDB_ERROR(NO_RECOVERY)
+};
+
+enum addrinfo_errors
+{
+  /// The service is not supported for the given socket type.
+  service_not_found = ASIO_WIN_OR_POSIX(
+      ASIO_NATIVE_ERROR(WSATYPE_NOT_FOUND),
+      ASIO_GETADDRINFO_ERROR(EAI_SERVICE)),
+
+  /// The socket type is not supported.
+  socket_type_not_supported = ASIO_WIN_OR_POSIX(
+      ASIO_NATIVE_ERROR(WSAESOCKTNOSUPPORT),
+      ASIO_GETADDRINFO_ERROR(EAI_SOCKTYPE))
+};
+
+enum misc_errors
+{
+  /// Already open.
+  already_open = 1,
+
+  /// End of file or stream.
+  eof,
+
+  /// Element not found.
+  not_found
 };
 
 // boostify: error category definitions go here.
 
-template <typename T> const asio::error_code
-error_base<T>::access_denied = ASIO_SOCKET_ERROR(EACCES);
-
-template <typename T> const asio::error_code
-error_base<T>::address_family_not_supported = ASIO_SOCKET_ERROR(
-    EAFNOSUPPORT);
-
-template <typename T> const asio::error_code
-error_base<T>::address_in_use = ASIO_SOCKET_ERROR(EADDRINUSE);
-
-template <typename T> const asio::error_code
-error_base<T>::already_connected = ASIO_SOCKET_ERROR(EISCONN);
-
-template <typename T> const asio::error_code
-error_base<T>::already_open = ASIO_MISC_ERROR(1);
-
-template <typename T> const asio::error_code
-error_base<T>::already_started = ASIO_SOCKET_ERROR(EALREADY);
-
-template <typename T> const asio::error_code
-error_base<T>::connection_aborted = ASIO_SOCKET_ERROR(ECONNABORTED);
-
-template <typename T> const asio::error_code
-error_base<T>::connection_refused = ASIO_SOCKET_ERROR(ECONNREFUSED);
-
-template <typename T> const asio::error_code
-error_base<T>::connection_reset = ASIO_SOCKET_ERROR(ECONNRESET);
-
-template <typename T> const asio::error_code
-error_base<T>::bad_descriptor = ASIO_SOCKET_ERROR(EBADF);
-
-template <typename T> const asio::error_code
-error_base<T>::eof = ASIO_MISC_ERROR(2);
-
-template <typename T> const asio::error_code
-error_base<T>::fault = ASIO_SOCKET_ERROR(EFAULT);
-
-template <typename T> const asio::error_code
-error_base<T>::host_not_found = ASIO_NETDB_ERROR(HOST_NOT_FOUND);
-
-template <typename T> const asio::error_code
-error_base<T>::host_not_found_try_again = ASIO_NETDB_ERROR(TRY_AGAIN);
-
-template <typename T> const asio::error_code
-error_base<T>::host_unreachable = ASIO_SOCKET_ERROR(EHOSTUNREACH);
-
-template <typename T> const asio::error_code
-error_base<T>::in_progress = ASIO_SOCKET_ERROR(EINPROGRESS);
-
-template <typename T> const asio::error_code
-error_base<T>::interrupted = ASIO_SOCKET_ERROR(EINTR);
-
-template <typename T> const asio::error_code
-error_base<T>::invalid_argument = ASIO_SOCKET_ERROR(EINVAL);
-
-template <typename T> const asio::error_code
-error_base<T>::message_size = ASIO_SOCKET_ERROR(EMSGSIZE);
-
-template <typename T> const asio::error_code
-error_base<T>::network_down = ASIO_SOCKET_ERROR(ENETDOWN);
-
-template <typename T> const asio::error_code
-error_base<T>::network_reset = ASIO_SOCKET_ERROR(ENETRESET);
-
-template <typename T> const asio::error_code
-error_base<T>::network_unreachable = ASIO_SOCKET_ERROR(ENETUNREACH);
-
-template <typename T> const asio::error_code
-error_base<T>::no_descriptors = ASIO_SOCKET_ERROR(EMFILE);
-
-template <typename T> const asio::error_code
-error_base<T>::no_buffer_space = ASIO_SOCKET_ERROR(ENOBUFS);
-
-template <typename T> const asio::error_code
-error_base<T>::no_data = ASIO_NETDB_ERROR(NO_DATA);
-
-template <typename T> const asio::error_code
-error_base<T>::no_memory = ASIO_WIN_OR_POSIX(
-    ASIO_NATIVE_ERROR(ERROR_OUTOFMEMORY),
-    ASIO_NATIVE_ERROR(ENOMEM));
-
-template <typename T> const asio::error_code
-error_base<T>::no_permission = ASIO_WIN_OR_POSIX(
-    ASIO_NATIVE_ERROR(ERROR_ACCESS_DENIED),
-    ASIO_NATIVE_ERROR(EPERM));
-
-template <typename T> const asio::error_code
-error_base<T>::no_protocol_option = ASIO_SOCKET_ERROR(ENOPROTOOPT);
-
-template <typename T> const asio::error_code
-error_base<T>::no_recovery = ASIO_NETDB_ERROR(NO_RECOVERY);
-
-template <typename T> const asio::error_code
-error_base<T>::not_connected = ASIO_SOCKET_ERROR(ENOTCONN);
-
-template <typename T> const asio::error_code
-error_base<T>::not_found = ASIO_MISC_ERROR(3);
-
-template <typename T> const asio::error_code
-error_base<T>::not_socket = ASIO_SOCKET_ERROR(ENOTSOCK);
-
-template <typename T> const asio::error_code
-error_base<T>::operation_aborted = ASIO_WIN_OR_POSIX(
-    ASIO_NATIVE_ERROR(ERROR_OPERATION_ABORTED),
-    ASIO_NATIVE_ERROR(ECANCELED));
-
-template <typename T> const asio::error_code
-error_base<T>::operation_not_supported = ASIO_SOCKET_ERROR(EOPNOTSUPP);
-
-template <typename T> const asio::error_code
-error_base<T>::service_not_found = ASIO_WIN_OR_POSIX(
-    ASIO_NATIVE_ERROR(WSATYPE_NOT_FOUND),
-    ASIO_GETADDRINFO_ERROR(EAI_SERVICE));
-
-template <typename T> const asio::error_code
-error_base<T>::socket_type_not_supported = ASIO_WIN_OR_POSIX(
-    ASIO_NATIVE_ERROR(WSAESOCKTNOSUPPORT),
-    ASIO_GETADDRINFO_ERROR(EAI_SOCKTYPE));
-
-template <typename T> const asio::error_code
-error_base<T>::shut_down = ASIO_SOCKET_ERROR(ESHUTDOWN);
-
-template <typename T> const asio::error_code
-error_base<T>::timed_out = ASIO_SOCKET_ERROR(ETIMEDOUT);
-
-template <typename T> const asio::error_code
-error_base<T>::try_again = ASIO_WIN_OR_POSIX(
-    ASIO_NATIVE_ERROR(ERROR_RETRY),
-    ASIO_NATIVE_ERROR(EAGAIN));
-
-template <typename T> const asio::error_code
-error_base<T>::would_block = ASIO_SOCKET_ERROR(EWOULDBLOCK);
-
-} // namespace detail
-
-/// Contains error constants.
-class error : public asio::detail::error_base<error>
+inline asio::error_code make_error_code(basic_errors e)
 {
-private:
-  error();
-};
+  return asio::error_code(static_cast<int>(e), system_category);
+}
 
+inline asio::error_code make_error_code(netdb_errors e)
+{
+  return asio::error_code(static_cast<int>(e), netdb_category);
+}
+
+inline asio::error_code make_error_code(addrinfo_errors e)
+{
+  return asio::error_code(static_cast<int>(e), addrinfo_category);
+}
+
+inline asio::error_code make_error_code(misc_errors e)
+{
+  return asio::error_code(static_cast<int>(e), misc_category);
+}
+
+} // namespace error
 } // namespace asio
 
 #undef ASIO_NATIVE_ERROR
 #undef ASIO_SOCKET_ERROR
 #undef ASIO_NETDB_ERROR
 #undef ASIO_GETADDRINFO_ERROR
-#undef ASIO_MISC_ERROR
 #undef ASIO_WIN_OR_POSIX
 
 #include "asio/impl/error_code.ipp"
diff --git a/libtorrent/include/libtorrent/asio/error_code.hpp b/libtorrent/include/libtorrent/asio/error_code.hpp
index 0614490e2..0941a8c00 100644
--- a/libtorrent/include/libtorrent/asio/error_code.hpp
+++ b/libtorrent/include/libtorrent/asio/error_code.hpp
@@ -32,24 +32,27 @@
 
 namespace asio {
 
-/// Available error code categories.
-enum error_category
+namespace error
 {
-  /// Native error codes.
-  native_ecat = ASIO_WIN_OR_POSIX(0, 0),
+  /// Available error code categories.
+  enum error_category
+  {
+    /// System error codes.
+    system_category = ASIO_WIN_OR_POSIX(0, 0),
 
-  /// Error codes from NetDB functions.
-  netdb_ecat = ASIO_WIN_OR_POSIX(native_ecat, 1),
+    /// Error codes from NetDB functions.
+    netdb_category = ASIO_WIN_OR_POSIX(system_category, 1),
 
-  /// Error codes from getaddrinfo.
-  addrinfo_ecat = ASIO_WIN_OR_POSIX(native_ecat, 2),
+    /// Error codes from getaddrinfo.
+    addrinfo_category = ASIO_WIN_OR_POSIX(system_category, 2),
 
-  /// Miscellaneous error codes.
-  misc_ecat = ASIO_WIN_OR_POSIX(3, 3),
+    /// Miscellaneous error codes.
+    misc_category = ASIO_WIN_OR_POSIX(3, 3),
 
-  /// SSL error codes.
-  ssl_ecat = ASIO_WIN_OR_POSIX(4, 4)
-};
+    /// SSL error codes.
+    ssl_category = ASIO_WIN_OR_POSIX(4, 4)
+  };
+} // namespace error
 
 /// Class to represent an error code value.
 class error_code
@@ -61,17 +64,24 @@ public:
   /// Default constructor.
   error_code()
     : value_(0),
-      category_(native_ecat)
+      category_(error::system_category)
   {
   }
 
   /// Construct with specific error code and category.
-  error_code(value_type v, error_category c)
+  error_code(value_type v, error::error_category c)
     : value_(v),
       category_(c)
   {
   }
 
+  /// Construct from an error code enum.
+  template <typename ErrorEnum>
+  error_code(ErrorEnum e)
+  {
+    *this = make_error_code(e);
+  }
+
   /// Get the error value.
   value_type value() const
   {
@@ -79,7 +89,7 @@ public:
   }
 
   /// Get the error category.
-  error_category category() const
+  error::error_category category() const
   {
     return category_;
   }
@@ -125,7 +135,7 @@ private:
   value_type value_;
 
   // The category associated with the error code.
-  error_category category_;
+  error::error_category category_;
 };
 
 } // namespace asio
diff --git a/libtorrent/include/libtorrent/asio/impl/error_code.ipp b/libtorrent/include/libtorrent/asio/impl/error_code.ipp
index da2f98833..f66b6fd94 100644
--- a/libtorrent/include/libtorrent/asio/impl/error_code.ipp
+++ b/libtorrent/include/libtorrent/asio/impl/error_code.ipp
@@ -35,10 +35,12 @@ inline std::string error_code::message() const
     return "Already open.";
   if (*this == error::not_found)
     return "Not found.";
-  if (category_ == ssl_ecat)
+  if (category_ == error::ssl_category)
     return "SSL error.";
 #if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
   value_type value = value_;
+  if (category() != error::system_category && *this != error::eof)
+    return "asio error";
   if (*this == error::eof)
     value = ERROR_HANDLE_EOF;
   char* msg = 0;
@@ -76,6 +78,8 @@ inline std::string error_code::message() const
     return "Service not found.";
   if (*this == error::socket_type_not_supported)
     return "Socket type not supported.";
+  if (category() != error::system_category)
+    return "asio error";
 #if defined(__sun) || defined(__QNX__)
   return strerror(value_);
 #elif defined(__MACH__) && defined(__APPLE__) \
diff --git a/libtorrent/include/libtorrent/asio/impl/read_until.ipp b/libtorrent/include/libtorrent/asio/impl/read_until.ipp
index 64c15ec7d..8b69a11c6 100644
--- a/libtorrent/include/libtorrent/asio/impl/read_until.ipp
+++ b/libtorrent/include/libtorrent/asio/impl/read_until.ipp
@@ -311,7 +311,8 @@ namespace detail
       if (streambuf_.size() == streambuf_.max_size())
       {
         std::size_t bytes = 0;
-        handler_(error::not_found, bytes);
+        asio::error_code ec(error::not_found);
+        handler_(ec, bytes);
         return;
       }
 
@@ -388,7 +389,8 @@ void async_read_until(AsyncReadStream& s,
   // No match. Check if buffer is full.
   if (b.size() == b.max_size())
   {
-    s.io_service().post(detail::bind_handler(handler, error::not_found, 0));
+    asio::error_code ec(error::not_found);
+    s.io_service().post(detail::bind_handler(handler, ec, 0));
     return;
   }
 
@@ -469,7 +471,8 @@ namespace detail
       if (streambuf_.size() == streambuf_.max_size())
       {
         std::size_t bytes = 0;
-        handler_(error::not_found, bytes);
+        asio::error_code ec(error::not_found);
+        handler_(ec, bytes);
         return;
       }
 
@@ -559,7 +562,8 @@ void async_read_until(AsyncReadStream& s,
   // Check if buffer is full.
   if (b.size() == b.max_size())
   {
-    s.io_service().post(detail::bind_handler(handler, error::not_found, 0));
+    asio::error_code ec(error::not_found);
+    s.io_service().post(detail::bind_handler(handler, ec, 0));
     return;
   }
 
@@ -641,7 +645,8 @@ namespace detail
       if (streambuf_.size() == streambuf_.max_size())
       {
         std::size_t bytes = 0;
-        handler_(error::not_found, bytes);
+        asio::error_code ec(error::not_found);
+        handler_(ec, bytes);
         return;
       }
 
@@ -731,7 +736,8 @@ void async_read_until(AsyncReadStream& s,
   // Check if buffer is full.
   if (b.size() == b.max_size())
   {
-    s.io_service().post(detail::bind_handler(handler, error::not_found, 0));
+    asio::error_code ec(error::not_found);
+    s.io_service().post(detail::bind_handler(handler, ec, 0));
     return;
   }
 
diff --git a/libtorrent/include/libtorrent/asio/ip/basic_endpoint.hpp b/libtorrent/include/libtorrent/asio/ip/basic_endpoint.hpp
index 499d82631..3d1316e22 100644
--- a/libtorrent/include/libtorrent/asio/ip/basic_endpoint.hpp
+++ b/libtorrent/include/libtorrent/asio/ip/basic_endpoint.hpp
@@ -307,7 +307,7 @@ public:
 private:
   // Helper function to determine whether the endpoint is IPv4.
 #if defined(_AIX)
-  template <typename T, unsigned short (T::*)> struct is_v4_helper {};
+  template <typename T, unsigned char (T::*)> struct is_v4_helper {};
 
   template <typename T>
   static bool is_v4(const T& ss, is_v4_helper<T, &T::ss_family>* = 0)
diff --git a/libtorrent/include/libtorrent/asio/ssl/detail/openssl_operation.hpp b/libtorrent/include/libtorrent/asio/ssl/detail/openssl_operation.hpp
index b7a564464..5fd3ebba4 100755
--- a/libtorrent/include/libtorrent/asio/ssl/detail/openssl_operation.hpp
+++ b/libtorrent/include/libtorrent/asio/ssl/detail/openssl_operation.hpp
@@ -174,12 +174,12 @@ public:
       if (error_code == SSL_ERROR_SYSCALL)
       {
         return handler_(asio::error_code(
-              sys_error_code, asio::native_ecat), rc); 
+              sys_error_code, asio::error::system_category), rc); 
       }
       else
       {
         return handler_(asio::error_code(
-              error_code, asio::ssl_ecat), rc); 
+              error_code, asio::error::ssl_category), rc); 
       }
     }
 
diff --git a/libtorrent/include/libtorrent/peer_connection.hpp b/libtorrent/include/libtorrent/peer_connection.hpp
index 5e65f767a..ea16a8d0a 100755
--- a/libtorrent/include/libtorrent/peer_connection.hpp
+++ b/libtorrent/include/libtorrent/peer_connection.hpp
@@ -155,8 +155,7 @@ namespace libtorrent
 
 		int prefer_whole_pieces() const
 		{
-			if (m_prefer_whole_pieces == 0)
-				return peer_info_struct() && peer_info_struct()->on_parole ? 1 : 0;
+			if (on_parole()) return 1;
 			return m_prefer_whole_pieces;
 		}
 
diff --git a/libtorrent/include/libtorrent/peer_info.hpp b/libtorrent/include/libtorrent/peer_info.hpp
index 82a4675e7..046df2a6b 100755
--- a/libtorrent/include/libtorrent/peer_info.hpp
+++ b/libtorrent/include/libtorrent/peer_info.hpp
@@ -117,6 +117,11 @@ namespace libtorrent
 		// for yet
 		int download_queue_length;
 
+		// the number of requests that is
+		// tried to be maintained (this is
+		// typically a function of download speed)
+		int target_dl_queue_length;
+
 		// this is the number of requests
 		// the peer has sent to us
 		// that we haven't sent yet
diff --git a/libtorrent/include/libtorrent/storage.hpp b/libtorrent/include/libtorrent/storage.hpp
index 80f12588b..e52196c76 100755
--- a/libtorrent/include/libtorrent/storage.hpp
+++ b/libtorrent/include/libtorrent/storage.hpp
@@ -201,8 +201,8 @@ namespace libtorrent
 
 		void async_read(
 			peer_request const& r
-            , boost::function<void(int, disk_io_job const&)> const& handler
-            , char* buffer = 0);
+			, boost::function<void(int, disk_io_job const&)> const& handler
+			, char* buffer = 0);
 
 		void async_write(
 			peer_request const& r
diff --git a/libtorrent/src/Makefile.am b/libtorrent/src/Makefile.am
index ede56a893..671cb75e5 100644
--- a/libtorrent/src/Makefile.am
+++ b/libtorrent/src/Makefile.am
@@ -97,4 +97,3 @@ libtorrent_la_LIBADD = @ZLIB@ -l@BOOST_DATE_TIME_LIB@ -l@BOOST_FILESYSTEM_LIB@ -
 AM_CXXFLAGS= -ftemplate-depth-50 -I$(top_srcdir)/include -I$(top_srcdir)/include/libtorrent @ZLIBINCL@ @DEBUGFLAGS@ @PTHREAD_CFLAGS@ -DBOOST_MULTI_INDEX_DISABLE_SERIALIZATION
 AM_LDFLAGS= $(LDFLAGS) -l@BOOST_DATE_TIME_LIB@ -l@BOOST_FILESYSTEM_LIB@ -l@BOOST_THREAD_LIB@ @PTHREAD_LIBS@
 
-
diff --git a/libtorrent/src/disk_io_thread.cpp b/libtorrent/src/disk_io_thread.cpp
index 9e7471db5..e07a884cf 100644
--- a/libtorrent/src/disk_io_thread.cpp
+++ b/libtorrent/src/disk_io_thread.cpp
@@ -255,4 +255,3 @@ namespace libtorrent
 	}
 }
 
-
diff --git a/libtorrent/src/http_connection.cpp b/libtorrent/src/http_connection.cpp
index 03e0688de..2b306ca6d 100644
--- a/libtorrent/src/http_connection.cpp
+++ b/libtorrent/src/http_connection.cpp
@@ -385,4 +385,3 @@ void http_connection::rate_limit(int limit)
 
 }
 
-
diff --git a/libtorrent/src/peer_connection.cpp b/libtorrent/src/peer_connection.cpp
index a3d522b89..ad2102f0d 100755
--- a/libtorrent/src/peer_connection.cpp
+++ b/libtorrent/src/peer_connection.cpp
@@ -2019,8 +2019,9 @@ namespace libtorrent
 
 		p.load_balancing = total_free_upload();
 
-		p.download_queue_length = (int)download_queue().size();
-		p.upload_queue_length = (int)upload_queue().size();
+		p.download_queue_length = int(download_queue().size() + m_request_queue.size());
+		p.target_dl_queue_length = int(desired_queue_size());
+		p.upload_queue_length = int(upload_queue().size());
 
 		if (boost::optional<piece_block_progress> ret = downloading_piece_progress())
 		{
diff --git a/libtorrent/src/piece_picker.cpp b/libtorrent/src/piece_picker.cpp
index 8c8911e7c..8fa623fa3 100755
--- a/libtorrent/src/piece_picker.cpp
+++ b/libtorrent/src/piece_picker.cpp
@@ -1125,7 +1125,7 @@ namespace libtorrent
 			, interesting_blocks, backup_blocks, num_blocks
 			, prefer_whole_pieces, peer, speed, on_parole);
 
-		if (num_blocks == 0) return;
+		if (num_blocks <= 0) return;
 
 		if (rarest_first)
 		{
@@ -1364,6 +1364,13 @@ namespace libtorrent
 
 			if (prefer_whole_pieces > 0 && !exclusive_active) continue;
 
+			// don't pick too many back-up blocks
+			if (i->state != none
+				&& i->state != speed
+				&& !exclusive_active
+				&& int(backup_blocks.size()) >= num_blocks)
+				continue;
+
 			for (int j = 0; j < num_blocks_in_piece; ++j)
 			{
 				// ignore completed blocks and already requested blocks
@@ -1412,9 +1419,15 @@ namespace libtorrent
 		if (num_blocks <= 0) return 0;
 		if (on_parole) return num_blocks;
 
+		int to_copy;
+		if (prefer_whole_pieces == 0)
+			to_copy = (std::min)(int(backup_blocks.size()), num_blocks);
+		else
+			to_copy = int(backup_blocks.size());
+
 		interesting_blocks.insert(interesting_blocks.end()
-			, backup_blocks.begin(), backup_blocks.end());
-		num_blocks -= int(backup_blocks.size());
+			, backup_blocks.begin(), backup_blocks.begin() + to_copy);
+		num_blocks -= to_copy;
 		backup_blocks.clear();
 
 		if (num_blocks <= 0) return 0;
diff --git a/libtorrent/src/policy.cpp b/libtorrent/src/policy.cpp
index 3193ae455..6e81da0d5 100755
--- a/libtorrent/src/policy.cpp
+++ b/libtorrent/src/policy.cpp
@@ -284,6 +284,8 @@ namespace libtorrent
 		for (std::vector<piece_block>::iterator i = interesting_pieces.begin();
 			i != interesting_pieces.end(); ++i)
 		{
+			if (prefer_whole_pieces == 0 && num_requests <= 0) break;
+
 			if (p.is_requested(*i))
 			{
 				if (num_requests <= 0) break;
diff --git a/libtorrent/src/session_impl.cpp b/libtorrent/src/session_impl.cpp
index cfbb0e65a..0aeb84bbe 100755
--- a/libtorrent/src/session_impl.cpp
+++ b/libtorrent/src/session_impl.cpp
@@ -2380,4 +2380,3 @@ namespace detail
 	}
 }}
 
-
diff --git a/libtorrent/src/storage.cpp b/libtorrent/src/storage.cpp
index 258b91c95..e1ddd20ae 100755
--- a/libtorrent/src/storage.cpp
+++ b/libtorrent/src/storage.cpp
@@ -2209,4 +2209,3 @@ namespace libtorrent
 #endif
 } // namespace libtorrent
 
-
diff --git a/libtorrent/src/upnp.cpp b/libtorrent/src/upnp.cpp
index 103a71620..043cf4b94 100644
--- a/libtorrent/src/upnp.cpp
+++ b/libtorrent/src/upnp.cpp
@@ -994,4 +994,3 @@ void upnp::close()
 	}
 }
 
-