diff --git a/.clang-format b/.clang-format
index c171fd6..300ddea 100644
--- a/.clang-format
+++ b/.clang-format
@@ -19,6 +19,7 @@ AllowShortLambdasOnASingleLine:                  All
 
 AlwaysBreakTemplateDeclarations:                 Yes
 IndentPPDirectives:                              BeforeHash
+RequiresClausePosition:                          SingleLine
 
 BraceWrapping:
   AfterEnum:                                     false
diff --git a/src/ast.h b/src/ast.h
index b4af981..623ebcd 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <concepts>   // std::derived_from, std::same_as
 #include <cstdint>    // int64_t, uint8_t
 #include <functional> // std::function
 #include <list>
@@ -52,20 +53,30 @@ protected:
 
 // -----------------------------------------
 
+template<typename T>
+concept IsValue = std::same_as<Value, T> || std::derived_from<T, Value>;
+
 class Collection : public Value {
 public:
 	virtual ~Collection() = default;
 
 	void add(ValuePtr node);
 
-	const std::list<ValuePtr>& nodes() const { return m_nodes; }
 	size_t size() const { return m_nodes.size(); }
 	bool empty() const { return m_nodes.size() == 0; }
 
+	const std::list<ValuePtr>& nodes() const { return m_nodes; }
+
 protected:
 	Collection() = default;
 	Collection(const std::list<ValuePtr>& nodes);
 
+	template<IsValue... Ts>
+	Collection(std::shared_ptr<Ts>... nodes)
+	{
+		m_nodes = { nodes... };
+	}
+
 private:
 	virtual bool isCollection() const override { return true; }
 
@@ -79,6 +90,13 @@ class List final : public Collection {
 public:
 	List() = default;
 	List(const std::list<ValuePtr>& nodes);
+
+	template<IsValue... Ts>
+	List(std::shared_ptr<Ts>... nodes)
+		: Collection(nodes...)
+	{
+	}
+
 	virtual ~List() = default;
 
 private:
@@ -92,6 +110,13 @@ class Vector final : public Collection {
 public:
 	Vector() = default;
 	Vector(const std::list<ValuePtr>& nodes);
+
+	template<IsValue... Ts>
+	Vector(std::shared_ptr<Ts>... nodes)
+		: Collection(nodes...)
+	{
+	}
+
 	virtual ~Vector() = default;
 
 private:
diff --git a/src/eval.cpp b/src/eval.cpp
index 56a3f9e..8ea634a 100644
--- a/src/eval.cpp
+++ b/src/eval.cpp
@@ -253,10 +253,7 @@ static ValuePtr startsWith(ValuePtr ast, const std::string& symbol)
 static ValuePtr evalQuasiQuoteImpl(ValuePtr ast)
 {
 	if (is<HashMap>(ast.get()) || is<Symbol>(ast.get())) {
-		auto quoted_list = makePtr<List>();
-		quoted_list->add(makePtr<Symbol>("quote"));
-		quoted_list->add(ast);
-		return quoted_list;
+		return makePtr<List>(makePtr<Symbol>("quote"), ast);
 	}
 
 	if (!is<Collection>(ast.get())) {
@@ -283,32 +280,23 @@ static ValuePtr evalQuasiQuoteImpl(ValuePtr ast)
 	for (auto it = nodes.rbegin(); it != nodes.rend(); ++it) {
 		const auto elt = *it;
 
-		auto list = makePtr<List>();
-
 		const auto splice_unquote = startsWith(elt, "splice-unquote"); // (list 2 2 2)
 		if (splice_unquote) {
-			list->add(makePtr<Symbol>("concat"));
-			list->add(splice_unquote);
-			list->add(result);
-			result = list; // (cons 1 (concat (list 2 2 2) (cons 3 ())))
+			// (cons 1 (concat (list 2 2 2) (cons 3 ())))
+			result = makePtr<List>(makePtr<Symbol>("concat"), splice_unquote, result);
 			continue;
 		}
 
-		list->add(makePtr<Symbol>("cons"));
-		list->add(evalQuasiQuoteImpl(elt));
-		list->add(result);
-		result = list; // (cons 1 (cons 2 (cons 3 ())))
+		// (cons 1 (cons 2 (cons 3 ())))
+		result = makePtr<List>(makePtr<Symbol>("cons"), evalQuasiQuoteImpl(elt), result);
 	}
 
 	if (is<List>(ast.get())) {
 		return result;
 	}
 
-	// Wrap Vector in (vec)
-	auto vector = makePtr<List>();
-	vector->add(makePtr<Symbol>("vec"));
-	vector->add(result);
-	return vector;
+	// Wrap result in (vec) for Vector types
+	return makePtr<List>(makePtr<Symbol>("vec"), result);
 }
 
 void Eval::evalQuasiQuote(const std::list<ValuePtr>& nodes, EnvironmentPtr env)
diff --git a/src/functions.cpp b/src/functions.cpp
index 5818910..76b8da2 100644
--- a/src/functions.cpp
+++ b/src/functions.cpp
@@ -172,13 +172,7 @@ ADD_FUNCTION(">=", NUMBER_COMPARE(>=));
 ADD_FUNCTION(
 	"list",
 	{
-		auto list = makePtr<List>();
-
-		for (auto node : nodes) {
-			list->add(node);
-		}
-
-		return list;
+		return makePtr<List>(nodes);
 	});
 
 ADD_FUNCTION(