diff --git a/BAN/include/BAN/CircularQueue.h b/BAN/include/BAN/CircularQueue.h
index 57a84b43..28554c5c 100644
--- a/BAN/include/BAN/CircularQueue.h
+++ b/BAN/include/BAN/CircularQueue.h
@@ -24,7 +24,7 @@ namespace BAN
 		void push(const T&);
 		void push(T&&);
 		template<typename... Args>
-		void emplace(Args&&... args);
+		void emplace(Args&&... args) requires is_constructible_v<T, Args...>;
 
 		void pop();
 
@@ -71,7 +71,7 @@ namespace BAN
 
 	template<typename T, size_t S>
 	template<typename... Args>
-	void CircularQueue<T, S>::emplace(Args&&... args)
+	void CircularQueue<T, S>::emplace(Args&&... args) requires is_constructible_v<T, Args...>
 	{
 		ASSERT(!full());
 		new (element_at(((m_first + m_size) % capacity()))) T(BAN::forward<Args>(args)...);
diff --git a/BAN/include/BAN/HashMap.h b/BAN/include/BAN/HashMap.h
index edbe35f2..6f4f7e01 100644
--- a/BAN/include/BAN/HashMap.h
+++ b/BAN/include/BAN/HashMap.h
@@ -14,7 +14,7 @@ namespace BAN
 		struct Entry
 		{
 			template<typename... Args>
-			Entry(const Key& key, Args&&... args)
+			Entry(const Key& key, Args&&... args) requires is_constructible_v<T, Args...>
 				: key(key)
 				, value(forward<Args>(args)...)
 			{}
@@ -42,7 +42,7 @@ namespace BAN
 		ErrorOr<void> insert(const Key&, const T&);
 		ErrorOr<void> insert(const Key&, T&&);
 		template<typename... Args>
-		ErrorOr<void> emplace(const Key&, Args&&...);
+		ErrorOr<void> emplace(const Key&, Args&&...) requires is_constructible_v<T, Args...>;
 
 		iterator begin() { return iterator(m_buckets.end(), m_buckets.begin()); }
 		iterator end()   { return iterator(m_buckets.end(), m_buckets.end()); }
@@ -130,7 +130,7 @@ namespace BAN
 
 	template<typename Key, typename T, typename HASH>
 	template<typename... Args>
-	ErrorOr<void> HashMap<Key, T, HASH>::emplace(const Key& key, Args&&... args)
+	ErrorOr<void> HashMap<Key, T, HASH>::emplace(const Key& key, Args&&... args) requires is_constructible_v<T, Args...>
 	{
 		ASSERT(!contains(key));
 		TRY(rebucket(m_size + 1));
diff --git a/BAN/include/BAN/LinkedList.h b/BAN/include/BAN/LinkedList.h
index 79161f37..a7b5f3ad 100644
--- a/BAN/include/BAN/LinkedList.h
+++ b/BAN/include/BAN/LinkedList.h
@@ -34,9 +34,9 @@ namespace BAN
 		ErrorOr<void> insert(iterator, const T&);
 		ErrorOr<void> insert(iterator, T&&);
 		template<typename... Args>
-		ErrorOr<void> emplace_back(Args&&...);
+		ErrorOr<void> emplace_back(Args&&...) requires is_constructible_v<T, Args...>;
 		template<typename... Args>
-		ErrorOr<void> emplace(iterator, Args&&...);
+		ErrorOr<void> emplace(iterator, Args&&...) requires is_constructible_v<T, Args...>;
 
 		void pop_back();
 		iterator remove(iterator);
@@ -196,14 +196,14 @@ namespace BAN
 
 	template<typename T>
 	template<typename... Args>
-	ErrorOr<void> LinkedList<T>::emplace_back(Args&&... args)
+	ErrorOr<void> LinkedList<T>::emplace_back(Args&&... args) requires is_constructible_v<T, Args...>
 	{
 		return emplace(end(), forward<Args>(args)...);
 	}
 
 	template<typename T>
 	template<typename... Args>
-	ErrorOr<void> LinkedList<T>::emplace(iterator iter, Args&&... args)
+	ErrorOr<void> LinkedList<T>::emplace(iterator iter, Args&&... args) requires is_constructible_v<T, Args...>
 	{
 		Node* new_node = TRY(allocate_node(forward<Args>(args)...));
 		insert_node(iter, new_node);
diff --git a/BAN/include/BAN/Optional.h b/BAN/include/BAN/Optional.h
index ee893319..c5932474 100644
--- a/BAN/include/BAN/Optional.h
+++ b/BAN/include/BAN/Optional.h
@@ -25,7 +25,7 @@ namespace BAN
 		constexpr Optional& operator=(const Optional&);
 
 		template<typename... Args>
-		constexpr Optional& emplace(Args&&...);
+		constexpr Optional& emplace(Args&&...) requires is_constructible_v<T, Args...>;
 
 		constexpr T* operator->();
 		constexpr const T* operator->() const;
@@ -111,7 +111,7 @@ namespace BAN
 
 	template<typename T>
 	template<typename... Args>
-	constexpr Optional<T>& Optional<T>::emplace(Args&&... args)
+	constexpr Optional<T>& Optional<T>::emplace(Args&&... args) requires is_constructible_v<T, Args...>
 	{
 		clear();
 		m_has_value = true;
diff --git a/BAN/include/BAN/Queue.h b/BAN/include/BAN/Queue.h
index 5969189a..88d472ea 100644
--- a/BAN/include/BAN/Queue.h
+++ b/BAN/include/BAN/Queue.h
@@ -31,7 +31,7 @@ namespace BAN
 		ErrorOr<void> push(T&&);
 		ErrorOr<void> push(const T&);
 		template<typename... Args>
-		ErrorOr<void> emplace(Args&&...);
+		ErrorOr<void> emplace(Args&&...) requires is_constructible_v<T, Args...>;
 
 		ErrorOr<void> reserve(size_type);
 		ErrorOr<void> shrink_to_fit();
@@ -131,7 +131,7 @@ namespace BAN
 
 	template<typename T>
 	template<typename... Args>
-	ErrorOr<void> Queue<T>::emplace(Args&&... args)
+	ErrorOr<void> Queue<T>::emplace(Args&&... args) requires is_constructible_v<T, Args...>
 	{
 		TRY(ensure_capacity(m_size + 1));
 		new (m_data + m_size) T(forward<Args>(args)...);
diff --git a/BAN/include/BAN/RefPtr.h b/BAN/include/BAN/RefPtr.h
index 155de4e3..9f83ceb5 100644
--- a/BAN/include/BAN/RefPtr.h
+++ b/BAN/include/BAN/RefPtr.h
@@ -76,8 +76,9 @@ namespace BAN
 			return ptr;
 		}
 
+		// NOTE: don't use is_constructible_v<T, Args...> as RefPtr<T> is allowed with friends
 		template<typename... Args>
-		static ErrorOr<RefPtr> create(Args&&... args)
+		static ErrorOr<RefPtr> create(Args&&... args) requires requires(Args&&... args) { T(forward<Args>(args)...); }
 		{
 			T* pointer = new T(forward<Args>(args)...);
 			if (pointer == nullptr)
diff --git a/BAN/include/BAN/UniqPtr.h b/BAN/include/BAN/UniqPtr.h
index 3b49f575..7d21467b 100644
--- a/BAN/include/BAN/UniqPtr.h
+++ b/BAN/include/BAN/UniqPtr.h
@@ -33,8 +33,9 @@ namespace BAN
 			return uniq;
 		}
 
+		// NOTE: don't use is_constructible_v<T, Args...> as UniqPtr<T> is allowed with friends
 		template<typename... Args>
-		static BAN::ErrorOr<UniqPtr> create(Args&&... args)
+		static BAN::ErrorOr<UniqPtr> create(Args&&... args) requires requires(Args&&... args) { T(forward<Args>(args)...); }
 		{
 			UniqPtr uniq;
 			uniq.m_pointer = new T(BAN::forward<Args>(args)...);
diff --git a/BAN/include/BAN/Variant.h b/BAN/include/BAN/Variant.h
index d09617bb..0cdc8569 100644
--- a/BAN/include/BAN/Variant.h
+++ b/BAN/include/BAN/Variant.h
@@ -217,7 +217,7 @@ namespace BAN
 		}
 
 		template<typename T, typename... Args>
-		void emplace(Args&&... args) requires (can_have<T>())
+		void emplace(Args&&... args) requires (can_have<T>() && is_constructible_v<T, Args...>)
 		{
 			clear();
 			m_index = detail::index<T, Ts...>();
diff --git a/BAN/include/BAN/Vector.h b/BAN/include/BAN/Vector.h
index c58a111d..7583c175 100644
--- a/BAN/include/BAN/Vector.h
+++ b/BAN/include/BAN/Vector.h
@@ -35,9 +35,9 @@ namespace BAN
 		ErrorOr<void> push_back(T&&);
 		ErrorOr<void> push_back(const T&);
 		template<typename... Args>
-		ErrorOr<void> emplace_back(Args&&...);
+		ErrorOr<void> emplace_back(Args&&...) requires is_constructible_v<T, Args...>;
 		template<typename... Args>
-		ErrorOr<void> emplace(size_type, Args&&...);
+		ErrorOr<void> emplace(size_type, Args&&...) requires is_constructible_v<T, Args...>;
 		ErrorOr<void> insert(size_type, T&&);
 		ErrorOr<void> insert(size_type, const T&);
 
@@ -169,7 +169,7 @@ namespace BAN
 
 	template<typename T>
 	template<typename... Args>
-	ErrorOr<void> Vector<T>::emplace_back(Args&&... args)
+	ErrorOr<void> Vector<T>::emplace_back(Args&&... args) requires is_constructible_v<T, Args...>
 	{
 		TRY(ensure_capacity(m_size + 1));
 		new (m_data + m_size) T(forward<Args>(args)...);
@@ -179,7 +179,7 @@ namespace BAN
 
 	template<typename T>
 	template<typename... Args>
-	ErrorOr<void> Vector<T>::emplace(size_type index, Args&&... args)
+	ErrorOr<void> Vector<T>::emplace(size_type index, Args&&... args) requires is_constructible_v<T, Args...>
 	{
 		ASSERT(index <= m_size);
 		TRY(ensure_capacity(m_size + 1));