From 365557ddd7e2124c13ef48c286498ed3f58ea8d8 Mon Sep 17 00:00:00 2001
From: Jonne Ransijn <jonne@yyny.dev>
Date: Sat, 16 Nov 2024 23:52:11 +0100
Subject: [PATCH] AK: Add `IterableContainerOf` concept

This concept not only checks that the given type is iterable, but it
also checks that the iterated value is of the expected type.
---
 AK/Concepts.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/AK/Concepts.h b/AK/Concepts.h
index 51f1644f986..e6a7be77c44 100644
--- a/AK/Concepts.h
+++ b/AK/Concepts.h
@@ -122,6 +122,13 @@ concept IterableContainer = requires {
     } -> IteratorPairWith<decltype(declval<T>().end())>;
 };
 
+template<typename T, typename ValueT>
+concept IterableContainerOf = IterableContainer<T> && requires {
+    {
+        *declval<T>().begin()
+    } -> SameAs<ValueT>;
+};
+
 template<typename Func, typename... Args>
 concept FallibleFunction = requires(Func&& func, Args&&... args) {
     func(forward<Args>(args)...).is_error();
@@ -173,6 +180,7 @@ using AK::Concepts::Fundamental;
 using AK::Concepts::Indexable;
 using AK::Concepts::Integral;
 using AK::Concepts::IterableContainer;
+using AK::Concepts::IterableContainerOf;
 using AK::Concepts::IteratorFunction;
 using AK::Concepts::IteratorPairWith;
 using AK::Concepts::OneOf;