Missing member init (#1467)

initialize members of piece_block and use default member initialization.

include/libtorrent/aux_/session_impl.hpp

@@ -121,10 +121,6 @@ namespace libtorrent
 	struct listen_socket_t
 	{
 		listen_socket_t()
-			: tcp_external_port(0)
-			, udp_external_port(0)
-			, ssl(false)
-			, udp_write_blocked(false)
 		{
 			tcp_port_mapping[0] = -1;
 			tcp_port_mapping[1] = -1;
@@ -146,7 +142,7 @@ namespace libtorrent
 		// this is the port that was originally specified to listen on
 		// it may be different from local_endpoint.port() if we could
 		// had to retry binding with a higher port
-		int original_port;
+		int original_port = 0;
 
 		// this is typically set to the same as the local
 		// listen port. In case a NAT port forward was
@@ -155,21 +151,21 @@ namespace libtorrent
 		// on the NAT box itself. This is the port that has
 		// to be published to peers, since this is the port
 		// the client is reachable through.
-		int tcp_external_port;
-		int udp_external_port;
+		int tcp_external_port = 0;
+		int udp_external_port = 0;
 
 		// 0 is natpmp 1 is upnp
 		int tcp_port_mapping[2];
 		int udp_port_mapping[2];
 
 		// set to true if this is an SSL listen socket
-		bool ssl;
+		bool ssl = false;
 
 		// this is true when the udp socket send() has failed with EAGAIN or
 		// EWOULDBLOCK. i.e. we're currently waiting for the socket to become
 		// writeable again. Once it is, we'll set it to false and notify the utp
 		// socket manager
-		bool udp_write_blocked;
+		bool udp_write_blocked = false;
 
 		// the actual sockets (TCP listen socket and UDP socket)
 		// An entry does not necessarily have a UDP or TCP socket. One of these

include/libtorrent/piece_block.hpp

@@ -41,14 +41,14 @@ namespace libtorrent
 	{
 		static const piece_block invalid;
 
-		piece_block() : piece_index(0) {}
+		piece_block() = default;
 		piece_block(piece_index_t p_index, int b_index)
 			: piece_index(p_index)
 			, block_index(b_index)
 		{
 		}
-		piece_index_t piece_index;
-		int block_index;
+		piece_index_t piece_index {0};
+		int block_index = 0;
 
 		bool operator<(piece_block const& b) const
 		{

include/libtorrent/storage.hpp

@@ -285,9 +285,6 @@ namespace libtorrent
 		, public storage_piece_set
 		, boost::noncopyable
 	{
-		// hidden
-		storage_interface(): m_settings(0) {}
-
 
 		// This function is called when the storage is to be initialized. The
 		// default storage will create directories and empty files at this point.
@@ -448,11 +445,11 @@ namespace libtorrent
 		virtual ~storage_interface() {}
 
 		// initialized in disk_io_thread::perform_async_job
-		aux::session_settings* m_settings;
+		aux::session_settings* m_settings = nullptr;
 	private:
 
 		bool m_need_tick = false;
-		file_storage const* m_files;
+		file_storage const* m_files = nullptr;
 
 		// the reason for this to be a void pointer
 		// is to avoid creating a dependency on the