feat: allow disabling the logging of the library (#399)

Author: jmigual

CMakeLists.txt

@@ -7,6 +7,7 @@ PROJECT(sioclient
 option(BUILD_SHARED_LIBS "Build the shared library" OFF)
 option(BUILD_UNIT_TESTS "Builds unit tests target" OFF)
 option(USE_SUBMODULES "Use source in local submodules instead of system libraries" ON)
+option(DISABLE_LOGGING "Do not print logging messages" OFF)
 
 if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
     set(DEFAULT_BUILD_TYPE "Release")
@@ -39,6 +40,10 @@ add_definitions(
     -D_WEBSOCKETPP_CPP11_CHRONO_
 )
 
+if (DISABLE_LOGGING)
+    add_definitions(-DSIO_DISABLE_LOGGING)
+endif()
+
 set(ALL_SRC 
     "src/sio_client.cpp"
     "src/sio_socket.cpp"

src/internal/sio_client_impl.cpp

@@ -13,7 +13,7 @@
 #include <mutex>
 #include <cmath>
 // Comment this out to disable handshake logging to stdout
-#if DEBUG || _DEBUG
+#if (DEBUG || _DEBUG) && !defined(SIO_DISABLE_LOGGING)
 #define LOG(x) std::cout << x
 #else
 #define LOG(x)