Remove warnings (#284)

ixwebsocket/IXHttp.cpp

@@ -137,7 +137,7 @@ namespace ix
             {
                 contentLength = std::stoi(headers["Content-Length"]);
             }
-            catch (std::exception)
+            catch(const std::exception&)
             {
                 return std::make_tuple(
                     false, "Error parsing HTTP Header 'Content-Length'", httpRequest);

ixwebsocket/IXNetSystem.cpp

@@ -193,6 +193,7 @@ namespace ix
 #endif
     }
     
+#if defined(_WIN32) && defined(__GNUC__)
     static int hexval(unsigned c)
     {
         if (c - '0' < 10) return c - '0';
@@ -200,6 +201,7 @@ namespace ix
         if (c - 'a' < 6) return c - 'a' + 10;
         return -1;
     }
+#endif
 
     //
     // mingw does not have inet_pton, which were taken as is from the musl C library.

ixwebsocket/IXWebSocketServer.cpp

@@ -191,7 +191,6 @@ namespace ix
                         // Make sure the OS send buffer is flushed before moving on
                         do
                         {
-                            size_t bufferedAmount = client->bufferedAmount();
                             std::chrono::duration<double, std::milli> duration(500);
                             std::this_thread::sleep_for(duration);
                         } while (client->bufferedAmount() != 0);