Socket: adds closeOnDestruction flag to ctor arguments

Author: denizzzka

std/socket.d

@@ -2092,7 +2092,7 @@ static if (is(sockaddr_un))
         {
             auto address = new UnixAddress(name);
 
-            auto listener = new Socket(AddressFamily.UNIX, SocketType.STREAM);
+            auto listener = new Socket(AddressFamily.UNIX, SocketType.STREAM, true);
             scope(exit) listener.close();
             listener.bind(address);
             scope(exit) () @trusted { if (name[0]) remove(name.tempCString()); } ();
@@ -2661,6 +2661,7 @@ class Socket
 private:
     socket_t sock;
     AddressFamily _family;
+    const bool closeOnDestruction = true;
 
     version (Windows)
         bool _blocking = true;         /// Property to get or set whether the socket is blocking or nonblocking.
@@ -2772,10 +2773,20 @@ public:
         this._family = af;
     }
 
+    /// Use an existing socket handle.
+    ///
+    ///Params:
+    ///    closeOnDestruction = If failse doesn't close underlying system socket in the destructor.
+    this(socket_t sock, AddressFamily af, bool closeOnDestruction) pure nothrow @nogc
+    {
+        this.closeOnDestruction = closeOnDestruction;
+        this(sock, af);
+    }
 
     ~this() nothrow @nogc
     {
-        close();
+        if (closeOnDestruction)
+            close();
     }