From c38f43094036b83b7a575e723dd09f3873e0b585 Mon Sep 17 00:00:00 2001
From: LaEntropiaa <aadrian887mh@gmail.com>
Date: Sat, 21 Mar 2026 22:54:26 -0600
Subject: [PATCH] Added correct type restrains, concepts are really cool, not
 more horrible template metaprogramming, concepts make it mre clear, so sad
 that the industry will catch up to it until like 2038 or something

---
 include/linkedlist.h | 42 ++++++++++++++++++++++++++++--------------
 1 file changed, 28 insertions(+), 14 deletions(-)

diff --git a/include/linkedlist.h b/include/linkedlist.h
index bf9f6cf..24dbf58 100644
--- a/include/linkedlist.h
+++ b/include/linkedlist.h
@@ -1,11 +1,25 @@
 #ifndef LINKEDLIST_H
 #define LINKEDLIST_H
 
+#include <concepts>
 #include <cstdlib>
 #include <expected>
+#include <format>
 #include <new>
 #include <print>
 
+template <typename T>
+concept HasEqual = requires (T a, T b) {
+    {a == b} -> std::convertible_to<bool>;
+};
+
+template <typename T>
+concept LinkedListSupported =
+    std::formattable<T, char> &&
+    std::equality_comparable<T> &&
+    HasEqual<T>;
+
+
 /**
  * @brief Codigos de error para operaciones de LinkedList
  */
@@ -23,7 +37,7 @@ enum class LinkedListErr {
  * 
  * @tparam T Tipo de dato almacenado en el nodo
  */
-template<typename T>
+template<LinkedListSupported T>
 class Node {
 public:
     T data;          /**< Dato almacenado en el nodo */
@@ -38,7 +52,7 @@ public:
  * 
  * @tparam T Tipo de dato almacenado en la lista
  */
-template<typename T>
+template<LinkedListSupported T>
 class LinkedList {
 private:
     size_t size;     /**< Numero de elementos en la lista */
@@ -146,14 +160,14 @@ public:
     size_t len();
 };
 
-template <typename T>
+template <LinkedListSupported T>
 LinkedList<T>::LinkedList() {
     size = 0;
     head = nullptr;
     tail = nullptr;
 }
 
-template <typename T>
+template <LinkedListSupported T>
 LinkedList<T>::~LinkedList() {
     Node<T> *current = this->head;
 
@@ -164,7 +178,7 @@ LinkedList<T>::~LinkedList() {
     }
 }
 
-template <typename T>
+template <LinkedListSupported T>
 std::expected<T, LinkedListErr> LinkedList<T>::get(size_t index) {
     if (index >= this->size) {
         return std::unexpected(LinkedListErr::LINKEDLIST_OUT_OF_BOUNDS);
@@ -182,7 +196,7 @@ std::expected<T, LinkedListErr> LinkedList<T>::get(size_t index) {
     return current->data;
 }
 
-template <typename T>
+template <LinkedListSupported T>
 LinkedListErr LinkedList<T>::set(size_t index, const T& val) {
     if (index >= this->size) {
         return LinkedListErr::LINKEDLIST_OUT_OF_BOUNDS;
@@ -201,7 +215,7 @@ LinkedListErr LinkedList<T>::set(size_t index, const T& val) {
     return LinkedListErr::LINKEDLIST_OK;
 }
 
-template <typename T>
+template <LinkedListSupported T>
 LinkedListErr LinkedList<T>::insert(size_t index, const T& value) {
     if (this->is_empty()) {
         return this->append(value);
@@ -241,7 +255,7 @@ LinkedListErr LinkedList<T>::insert(size_t index, const T& value) {
     return LinkedListErr::LINKEDLIST_OK;
 }
 
-template <typename T>
+template <LinkedListSupported T>
 LinkedListErr LinkedList<T>::append(const T& value) {
     Node<T> *new_node = nullptr;
 
@@ -267,7 +281,7 @@ LinkedListErr LinkedList<T>::append(const T& value) {
     return LinkedListErr::LINKEDLIST_OK;
 }
 
-template <typename T>
+template <LinkedListSupported T>
 LinkedListErr LinkedList<T>::prepend(const T& value) {
     Node<T> *new_node = nullptr;
 
@@ -293,7 +307,7 @@ LinkedListErr LinkedList<T>::prepend(const T& value) {
     return LinkedListErr::LINKEDLIST_OK;
 }
 
-template <typename T>
+template <LinkedListSupported T>
 std::expected<T, LinkedListErr> LinkedList<T>::pop() {
     if (this->size == 0) {
         return std::unexpected(LinkedListErr::LINKEDLIST_EMPTY);
@@ -322,7 +336,7 @@ std::expected<T, LinkedListErr> LinkedList<T>::pop() {
     return return_val;
 }
 
-template <typename T>
+template <LinkedListSupported T>
 LinkedListErr LinkedList<T>::remove(size_t index) {
     if (index >= this->size) {
         return LinkedListErr::LINKEDLIST_OUT_OF_BOUNDS;
@@ -356,7 +370,7 @@ LinkedListErr LinkedList<T>::remove(size_t index) {
 }
 
 
-template <typename T>
+template <LinkedListSupported T>
 std::expected<size_t, LinkedListErr> LinkedList<T>::find(const T& value) {
     Node<T> *current = this->head;
     size_t count = 0;
@@ -372,7 +386,7 @@ std::expected<size_t, LinkedListErr> LinkedList<T>::find(const T& value) {
     return std::unexpected(LinkedListErr::LINKEDLIST_NOT_FOUND);
 }
 
-template <typename T>
+template <LinkedListSupported T>
 LinkedListErr LinkedList<T>::print() {
     if (this->size == 0) {
         return LinkedListErr::LINKEDLIST_OK;
@@ -392,7 +406,7 @@ LinkedListErr LinkedList<T>::print() {
     return LinkedListErr::LINKEDLIST_OK;
 }
 
-template <typename T>
+template <LinkedListSupported T>
 size_t LinkedList<T>::len() {
     return this->size;
 }