use C++ 20 (#82)

Author: eagleoflqj

.github/workflows/ci.yml

@@ -34,7 +34,7 @@ jobs:
 
       - uses: actions/setup-node@v4
         with:
-          node-version: 20.x
+          node-version: 22.x
 
       - name: Install node dependencies
         run: |

CMakeLists.txt

@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.27)
 
 project(fcitx5-webview)
 
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 

include/webview_candidate_window.hpp

@@ -134,7 +134,7 @@ class WebviewCandidateWindow : public CandidateWindow {
     template <typename F> inline void bind(const std::string &name, F f) {
         using Ret = typename function_traits<F>::return_type;
         using ArgsTp = typename function_traits<F>::args_tuple;
-        auto handler = [=](std::string args_json) -> std::string {
+        auto handler = [=, this](std::string args_json) -> std::string {
             auto j = nlohmann::json::parse(args_json);
             ArgsTp args;
             if (std::tuple_size<ArgsTp>() > j.size()) {