* fixed bug: check connection status before closing channel

include/cppamqp/connection.h

@@ -34,6 +34,8 @@ namespace cppamqp
         std::unique_ptr<internal> _internal;
 
     public:
+        inline operator bool() const;
+
         inline amqp_connection_state_t&        handle      ();
         inline const amqp_connection_state_t&  handle      () const;
 

include/cppamqp/connection.inl

@@ -35,6 +35,9 @@ namespace cppamqp
         return value;
     }
 
+    connection::operator bool() const
+        { return static_cast<bool>(_internal); }
+
     amqp_connection_state_t& connection::handle()
     {
         if (!_internal)

src/cppamqp/channel.cpp

@@ -20,7 +20,7 @@ channel::internal::internal(const cppamqp::connection& p_connection, channel_num
 
 channel::internal::~internal()
 {
-    if (handle <= 0)
+    if (handle <= 0 || !static_cast<bool>(connection))
         return;
     __impl::check_and_raise(
         amqp_channel_close(connection.handle(), handle, AMQP_REPLY_SUCCESS),