From 5a0ad6812c2406dcd3a3611449605b53d8beef0b Mon Sep 17 00:00:00 2001
From: Ali Mohammad Pur <ali.mpfard@gmail.com>
Date: Sat, 8 Jul 2023 14:08:25 +0330
Subject: [PATCH] AK: Add a CallableAs<R, Args...> concept

This is just the concept version of the IsCallableWithArguments type
trait previously defined in Function.h.
---
 AK/Concepts.h | 28 ++++++++++++++++++++++++++++
 AK/Function.h | 17 -----------------
 2 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/AK/Concepts.h b/AK/Concepts.h
index 461f776472..51f1644f98 100644
--- a/AK/Concepts.h
+++ b/AK/Concepts.h
@@ -129,6 +129,33 @@ concept FallibleFunction = requires(Func&& func, Args&&... args) {
     func(forward<Args>(args)...).release_value();
 };
 
+}
+namespace AK::Detail {
+
+template<typename T, typename Out, typename... Args>
+inline constexpr bool IsCallableWithArguments = requires(T t) {
+    {
+        t(declval<Args>()...)
+    } -> Concepts::ConvertibleTo<Out>;
+} || requires(T t) {
+    {
+        t(declval<Args>()...)
+    } -> Concepts::SameAs<Out>;
+};
+
+}
+
+namespace AK {
+
+using Detail::IsCallableWithArguments;
+
+}
+
+namespace AK::Concepts {
+
+template<typename Func, typename R, typename... Args>
+concept CallableAs = Detail::IsCallableWithArguments<Func, R, Args...>;
+
 }
 
 #if !USING_AK_GLOBALLY
@@ -136,6 +163,7 @@ namespace AK {
 #endif
 using AK::Concepts::Arithmetic;
 using AK::Concepts::ArrayLike;
+using AK::Concepts::CallableAs;
 using AK::Concepts::ConvertibleTo;
 using AK::Concepts::DerivedFrom;
 using AK::Concepts::Enum;
diff --git a/AK/Function.h b/AK/Function.h
index 90ec3c3752..59a97e8346 100644
--- a/AK/Function.h
+++ b/AK/Function.h
@@ -36,23 +36,6 @@
 
 namespace AK {
 
-namespace Detail {
-
-template<typename T, typename Out, typename... Args>
-inline constexpr bool IsCallableWithArguments = requires(T t) {
-    {
-        t(declval<Args>()...)
-    } -> ConvertibleTo<Out>;
-} || requires(T t) {
-    {
-        t(declval<Args>()...)
-    } -> SameAs<Out>;
-};
-
-}
-
-using Detail::IsCallableWithArguments;
-
 template<typename>
 class Function;