test: [[nodiscard]], const-correctness and other linter related stuff

test/entt/signal/dispatcher.cpp

@@ -30,11 +30,10 @@ struct receiver {
 
 TEST(Dispatcher, Functionalities) {
     entt::dispatcher dispatcher{};
-    entt::dispatcher other{};
     receiver receiver{};
 
-    ASSERT_NO_FATAL_FAILURE(entt::dispatcher{std::move(dispatcher)});
-    ASSERT_NO_FATAL_FAILURE(dispatcher = std::move(other));
+    ASSERT_NO_FATAL_FAILURE([[maybe_unused]] const entt::dispatcher other{entt::dispatcher{}});
+    ASSERT_NO_FATAL_FAILURE(dispatcher = entt::dispatcher{});
 
     ASSERT_EQ(dispatcher.size<an_event>(), 0u);
     ASSERT_EQ(dispatcher.size(), 0u);
@@ -187,14 +186,14 @@ TEST(Dispatcher, NamedQueue) {
 }
 
 TEST(Dispatcher, CustomAllocator) {
-    std::allocator<void> allocator{};
+    const std::allocator<void> allocator{};
     entt::dispatcher dispatcher{allocator};
 
     ASSERT_EQ(dispatcher.get_allocator(), allocator);
     ASSERT_FALSE(dispatcher.get_allocator() != allocator);
 
     dispatcher.enqueue<an_event>();
-    decltype(dispatcher) other{std::move(dispatcher), allocator};
+    const decltype(dispatcher) other{std::move(dispatcher), allocator};
 
     ASSERT_EQ(other.size<an_event>(), 1u);
 }

test/entt/signal/emitter.cpp

@@ -143,7 +143,7 @@ TEST(Emitter, On) {
 
 TEST(Emitter, OnAndErase) {
     test_emitter emitter{};
-    std::function<void(bar_event &, test_emitter &)> func{};
+    const std::function<void(bar_event &, test_emitter &)> func{};
 
     emitter.on(func);
 
@@ -157,14 +157,14 @@ TEST(Emitter, OnAndErase) {
 }
 
 TEST(Emitter, CustomAllocator) {
-    std::allocator<void> allocator{};
+    const std::allocator<void> allocator{};
     test_emitter emitter{allocator};
 
     ASSERT_EQ(emitter.get_allocator(), allocator);
     ASSERT_FALSE(emitter.get_allocator() != allocator);
 
     emitter.on<foo_event>([](auto &, const auto &) {});
-    decltype(emitter) other{std::move(emitter), allocator};
+    const decltype(emitter) other{std::move(emitter), allocator};
 
     ASSERT_TRUE(emitter.empty());
     ASSERT_FALSE(other.empty());

test/entt/signal/sigh.cpp

@@ -8,12 +8,12 @@ struct sigh_listener {
         v = 42;
     }
 
-    bool g(int) {
+    [[nodiscard]] bool g(int) {
         k = !k;
         return true;
     }
 
-    bool h(const int &) {
+    [[nodiscard]] bool h(const int &) {
         return k;
     }
 
@@ -60,8 +60,8 @@ TEST(SigH, Lifetime) {
 
     ASSERT_NO_FATAL_FAILURE(signal{src});
     ASSERT_NO_FATAL_FAILURE(signal{std::move(other)});
-    ASSERT_NO_FATAL_FAILURE(src = other);
-    ASSERT_NO_FATAL_FAILURE(src = std::move(other));
+    ASSERT_NO_FATAL_FAILURE(src = other);            // NOLINT
+    ASSERT_NO_FATAL_FAILURE(src = std::move(other)); // NOLINT
 
     ASSERT_NO_FATAL_FAILURE(delete new signal{});
 }
@@ -90,7 +90,7 @@ TEST(SigH, Swap) {
     entt::sigh<void(int &)> sigh1;
     entt::sigh<void(int &)> sigh2;
     entt::sink sink1{sigh1};
-    entt::sink sink2{sigh2};
+    const entt::sink sink2{sigh2};
 
     sink1.connect<&sigh_listener::f>();