some windows fixes for dynamic linking

include/libtorrent/aux_/session_impl.hpp

@@ -89,12 +89,12 @@ namespace libtorrent
 	class upnp;
 	class natpmp;
 	class lsd;
-	class fingerprint;
+	struct fingerprint;
 	class torrent;
 
 	namespace dht
 	{
-		class dht_tracker;
+		struct dht_tracker;
 	};
 
 	namespace aux

include/libtorrent/config.hpp

@@ -53,6 +53,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #elif defined(BOOST_MSVC)
 
 #pragma warning(disable: 4258)
+#pragma warning(disable: 4251)
 
 # if defined(TORRENT_BUILDING_SHARED)
 #  define TORRENT_EXPORT __declspec(dllexport)

include/libtorrent/connection_queue.hpp

@@ -47,7 +47,7 @@ POSSIBILITY OF SUCH DAMAGE.
 namespace libtorrent
 {
 
-class connection_queue : public boost::noncopyable
+class TORRENT_EXPORT connection_queue : public boost::noncopyable
 {
 public:
 	connection_queue(io_service& ios);

include/libtorrent/disk_buffer_holder.hpp

@@ -40,8 +40,8 @@ POSSIBILITY OF SUCH DAMAGE.
 namespace libtorrent
 {
 
-	namespace aux { class session_impl; }
-	class disk_buffer_pool;
+	namespace aux { struct session_impl; }
+	struct disk_buffer_pool;
 
 	struct TORRENT_EXPORT disk_buffer_holder
 	{

include/libtorrent/error_code.hpp

@@ -93,7 +93,7 @@ namespace libtorrent
 		{ return boost::system::error_condition(ev, *this); }
 	};
 
-	extern libtorrent_error_category libtorrent_category;
+	extern TORRENT_EXPORT libtorrent_error_category libtorrent_category;
 
 	using boost::system::error_code;
 	inline boost::system::error_category const& get_system_category()

include/libtorrent/natpmp.hpp

@@ -47,7 +47,7 @@ namespace libtorrent
 // std::string: error message
 typedef boost::function<void(int, int, std::string const&)> portmap_callback_t;
 
-class natpmp : public intrusive_ptr_base<natpmp>
+class TORRENT_EXPORT natpmp : public intrusive_ptr_base<natpmp>
 {
 public:
 	natpmp(io_service& ios, address const& listen_interface, portmap_callback_t const& cb);

include/libtorrent/upnp.hpp

@@ -62,7 +62,7 @@ namespace libtorrent
 // an informational log message
 typedef boost::function<void(int, int, std::string const&)> portmap_callback_t;
 
-class upnp : public intrusive_ptr_base<upnp>
+class TORRENT_EXPORT upnp : public intrusive_ptr_base<upnp>
 {
 public:
 	upnp(io_service& ios, connection_queue& cc

src/error_code.cpp

@@ -76,7 +76,7 @@ namespace libtorrent
 		return msgs[ev];
 	}
 
-	libtorrent_error_category libtorrent_category;
+	TORRENT_EXPORT libtorrent_error_category libtorrent_category;
 
 #else
 

test/setup_transfer.hpp

@@ -39,7 +39,7 @@ POSSIBILITY OF SUCH DAMAGE.
 namespace libtorrent
 {
 	class alert;
-	class add_torrent_params;
+	struct add_torrent_params;
 }
 
 bool print_alerts(libtorrent::session& ses, char const* name