From 7ba672139cea5459e2afb166933a4a28dfd6fb13 Mon Sep 17 00:00:00 2001
From: vittorioromeo <vittorio.romeo@outlook.com>
Date: Tue, 9 Jul 2024 16:34:55 +0200
Subject: [PATCH] Simplify `sf::WindowBase::handleEvents` and add basic tests

---
 include/SFML/Window/WindowBase.inl | 19 ++++++-------------
 test/Window/WindowBase.test.cpp    | 17 +++++++++++++++++
 2 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/include/SFML/Window/WindowBase.inl b/include/SFML/Window/WindowBase.inl
index 52b25791c..594692ef7 100644
--- a/include/SFML/Window/WindowBase.inl
+++ b/include/SFML/Window/WindowBase.inl
@@ -28,7 +28,7 @@
 #include <SFML/Window/Event.hpp>
 #include <SFML/Window/WindowBase.hpp> // NOLINT(misc-header-include-cycle)
 
-#include <type_traits>
+#include <utility>
 
 
 namespace sf
@@ -43,22 +43,13 @@ struct OverloadSet : Ts...
 template <typename... Ts>
 OverloadSet(Ts...) -> OverloadSet<Ts...>;
 
-template <typename... Ts>
-struct OverloadSetWithDefault : OverloadSet<Ts...>
+struct DelayOverloadResolution
 {
-    // By providing our own operator() and forwarding based
-    // on invocability of OverloadSet<Ts...> on the concrete type
-    // of the value, we save the user from having to provide
-    // their own catch-all overload if they don't want to
     template <typename T>
-    void operator()([[maybe_unused]] T&& value) // NOLINT(cppcoreguidelines-missing-std-forward)
+    DelayOverloadResolution(const T&)
     {
-        if constexpr (std::is_invocable_v<OverloadSet<Ts...>, T>)
-            OverloadSet<Ts...>::operator()(std::forward<T>(value));
     }
 };
-template <typename... Ts>
-OverloadSetWithDefault(Ts...) -> OverloadSetWithDefault<Ts...>;
 } // namespace priv
 
 
@@ -68,7 +59,9 @@ void WindowBase::handleEvents(Ts&&... handlers) // NOLINT(cppcoreguidelines-miss
 {
     // Disable misc-const-correctness for this line since clang-tidy
     // complains about it even though the code would become uncompilable
-    priv::OverloadSetWithDefault overloadSet{std::forward<Ts>(handlers)...}; // NOLINT(misc-const-correctness)
+
+    // NOLINTNEXTLINE(misc-const-correctness)
+    priv::OverloadSet overloadSet{std::forward<Ts>(handlers)..., [](const priv::DelayOverloadResolution&) { /* ignore */ }};
 
     while (const std::optional event = pollEvent())
         event->visit(overloadSet);
diff --git a/test/Window/WindowBase.test.cpp b/test/Window/WindowBase.test.cpp
index 76b862b7f..ab910091e 100644
--- a/test/Window/WindowBase.test.cpp
+++ b/test/Window/WindowBase.test.cpp
@@ -195,4 +195,21 @@ TEST_CASE("[Window] sf::WindowBase", runDisplayTests())
         CHECK(windowBase.getSize() == sf::Vector2u(200, 300));
         windowBase.setMinimumSize(sf::Vector2u(200, 300));
     }
+
+    SECTION("handleEvents()")
+    {
+        sf::WindowBase windowBase(sf::VideoMode({360, 240}), "WindowBase Tests");
+
+        // Should compile if user provides nothing
+        windowBase.handleEvents();
+
+        // Should compile if user provides only a specific handler
+        windowBase.handleEvents([](const sf::Event::Closed&) {});
+
+        // Should compile if user provides only a catch-all
+        windowBase.handleEvents([](const auto&) {});
+
+        // Should compile if user provides both a specific handler and a catch-all
+        windowBase.handleEvents([](const sf::Event::Closed&) {}, [](const auto&) {});
+    }
 }