initial commit

libraries/FastLED/src/fl/functional.h

@@ -0,0 +1,97 @@
+#pragma once
+#include "fl/type_traits.h"
+#include "fl/utility.h"
+
+namespace fl {
+
+template <typename T>
+class Ptr; // Forward declare Ptr to avoid header inclusion
+
+template <typename T, typename Deleter>
+class unique_ptr; // Forward declare unique_ptr to avoid header inclusion
+
+//----------------------------------------------------------------------------
+// invoke implementation - equivalent to std::invoke from C++17
+//----------------------------------------------------------------------------
+
+namespace detail {
+
+// Helper to detect member data pointers
+template <typename T>
+struct is_member_data_pointer : false_type {};
+
+template <typename T, typename C>
+struct is_member_data_pointer<T C::*> : integral_constant<bool, !is_function<T>::value> {};
+
+// Helper to detect if T is a pointer type
+template <typename T>
+struct is_pointer_like : false_type {};
+
+template <typename T>
+struct is_pointer_like<T*> : true_type {};
+
+template <typename T>
+struct is_pointer_like<fl::Ptr<T>> : true_type {};
+
+template <typename T, typename Deleter>
+struct is_pointer_like<fl::unique_ptr<T, Deleter>> : true_type {};
+
+// Helper to detect if we should use pointer-to-member syntax
+template <typename T>
+struct use_pointer_syntax : is_pointer_like<typename remove_reference<T>::type> {};
+
+} // namespace detail
+
+// Main invoke function overloads
+
+// 1a. Member function pointer with object reference
+template <typename F, typename T1, typename... Args>
+auto invoke(F&& f, T1&& t1, Args&&... args)
+    -> enable_if_t<is_member_function_pointer<typename remove_reference<F>::type>::value &&
+                   !detail::use_pointer_syntax<T1>::value,
+                   decltype((fl::forward<T1>(t1).*f)(fl::forward<Args>(args)...))>
+{
+    return (fl::forward<T1>(t1).*f)(fl::forward<Args>(args)...);
+}
+
+// 1b. Member function pointer with pointer-like object
+template <typename F, typename T1, typename... Args>
+auto invoke(F&& f, T1&& t1, Args&&... args)
+    -> enable_if_t<is_member_function_pointer<typename remove_reference<F>::type>::value &&
+                   detail::use_pointer_syntax<T1>::value,
+                   decltype(((*fl::forward<T1>(t1)).*f)(fl::forward<Args>(args)...))>
+{
+    return ((*fl::forward<T1>(t1)).*f)(fl::forward<Args>(args)...);
+}
+
+// 2a. Member data pointer with object reference
+template <typename F, typename T1>
+auto invoke(F&& f, T1&& t1)
+    -> enable_if_t<detail::is_member_data_pointer<typename remove_reference<F>::type>::value &&
+                   !detail::use_pointer_syntax<T1>::value,
+                   decltype(fl::forward<T1>(t1).*f)>
+{
+    return fl::forward<T1>(t1).*f;
+}
+
+// 2b. Member data pointer with pointer-like object
+template <typename F, typename T1>
+auto invoke(F&& f, T1&& t1)
+    -> enable_if_t<detail::is_member_data_pointer<typename remove_reference<F>::type>::value &&
+                   detail::use_pointer_syntax<T1>::value,
+                   decltype((*fl::forward<T1>(t1)).*f)>
+{
+    return (*fl::forward<T1>(t1)).*f;
+}
+
+// 3. Regular callable (function pointer, lambda, functor)
+template <typename F, typename... Args>
+auto invoke(F&& f, Args&&... args)
+    -> enable_if_t<!is_member_function_pointer<typename remove_reference<F>::type>::value &&
+                   !detail::is_member_data_pointer<typename remove_reference<F>::type>::value,
+                   decltype(fl::forward<F>(f)(fl::forward<Args>(args)...))>
+{
+    return fl::forward<F>(f)(fl::forward<Args>(args)...);
+}
+
+} // namespace fl