[json] Add forward definition header (#5676)

simulation/halsim_ws_client/src/main/native/include/HALSimWS.h

@@ -12,15 +12,12 @@
 #include <WSProviderContainer.h>
 #include <WSProvider_SimDevice.h>
 #include <wpi/StringMap.h>
+#include <wpi/json_fwd.h>
 #include <wpinet/uv/Async.h>
 #include <wpinet/uv/Loop.h>
 #include <wpinet/uv/Tcp.h>
 #include <wpinet/uv/Timer.h>
 
-namespace wpi {
-class json;
-}  // namespace wpi
-
 namespace wpilibws {
 
 class HALSimWSClientConnection;

simulation/halsim_ws_client/src/main/native/include/HALSimWSClientConnection.h

@@ -8,6 +8,7 @@
 #include <utility>
 
 #include <HALSimBaseWebSocketConnection.h>
+#include <wpi/json_fwd.h>
 #include <wpi/mutex.h>
 #include <wpinet/WebSocket.h>
 #include <wpinet/uv/Buffer.h>
@@ -15,10 +16,6 @@
 
 #include "HALSimWS.h"
 
-namespace wpi {
-class json;
-}  // namespace wpi
-
 namespace wpilibws {
 
 class HALSimWS;

simulation/halsim_ws_core/src/main/native/include/HALSimBaseWebSocketConnection.h

@@ -6,7 +6,7 @@
 
 #include <memory>
 
-#include <wpi/json.h>
+#include <wpi/json_fwd.h>
 
 namespace wpilibws {
 

simulation/halsim_ws_core/src/main/native/include/WSHalProviders.h

@@ -10,7 +10,7 @@
 #include <string_view>
 
 #include <hal/simulation/NotifyListener.h>
-#include <wpi/json.h>
+#include <wpi/json_fwd.h>
 #include <wpi/mutex.h>
 
 #include "WSBaseProvider.h"

simulation/halsim_ws_server/src/main/native/include/HALSimHttpConnection.h

@@ -10,6 +10,7 @@
 #include <utility>
 
 #include <HALSimBaseWebSocketConnection.h>
+#include <wpi/json_fwd.h>
 #include <wpi/mutex.h>
 #include <wpinet/HttpWebSocketServerConnection.h>
 #include <wpinet/uv/AsyncFunction.h>
@@ -17,10 +18,6 @@
 
 #include "HALSimWeb.h"
 
-namespace wpi {
-class json;
-}  // namespace wpi
-
 namespace wpilibws {
 
 class HALSimHttpConnection

simulation/halsim_ws_server/src/main/native/include/HALSimWeb.h

@@ -13,14 +13,11 @@
 #include <WSProviderContainer.h>
 #include <WSProvider_SimDevice.h>
 #include <wpi/StringMap.h>
+#include <wpi/json_fwd.h>
 #include <wpinet/uv/Async.h>
 #include <wpinet/uv/Loop.h>
 #include <wpinet/uv/Tcp.h>
 
-namespace wpi {
-class json;
-}  // namespace wpi
-
 namespace wpilibws {
 
 class HALSimWeb : public std::enable_shared_from_this<HALSimWeb> {

simulation/halsim_xrp/src/main/native/cpp/XRP.cpp

@@ -7,6 +7,7 @@
 #include <fmt/format.h>
 #include <wpi/Endian.h>
 #include <wpi/MathExtras.h>
+#include <wpi/json.h>
 
 using namespace wpilibxrp;
 

simulation/halsim_xrp/src/main/native/include/HALSimXRP.h

@@ -12,6 +12,7 @@
 #include <HALSimBaseWebSocketConnection.h>
 #include <WSProviderContainer.h>
 #include <WSProvider_SimDevice.h>
+#include <wpi/json_fwd.h>
 #include <wpinet/uv/Async.h>
 #include <wpinet/uv/Buffer.h>
 #include <wpinet/uv/Loop.h>
@@ -20,10 +21,6 @@
 
 #include "XRP.h"
 
-namespace wpi {
-class json;
-}  // namespace wpi
-
 namespace wpilibxrp {
 
 // This masquerades as a "WebSocket" so that we can reuse the

simulation/halsim_xrp/src/main/native/include/XRP.h

@@ -9,7 +9,7 @@
 #include <span>
 #include <string>
 
-#include <wpi/json.h>
+#include <wpi/json_fwd.h>
 #include <wpinet/raw_uv_ostream.h>
 
 #define XRP_TAG_MOTOR 0x12