From 564cc1b765e982cdc8e71d1ed465dffa5bab2bc2 Mon Sep 17 00:00:00 2001
From: studiosi <david@studiosi.es>
Date: Sat, 15 Aug 2026 17:43:30 +0300
Subject: [PATCH] Solved: 20 - Classes and Objects

---
 .../include/classes_and_objects.hpp             |  4 ++--
 .../06_oop_basics/src/classes_and_objects.cpp   | 17 ++++++++++-------
 .../test/classes_and_objects_test.cpp           |  2 ++
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/modules/06_oop_basics/include/classes_and_objects.hpp b/modules/06_oop_basics/include/classes_and_objects.hpp
index 6a962ca..3c1769b 100644
--- a/modules/06_oop_basics/include/classes_and_objects.hpp
+++ b/modules/06_oop_basics/include/classes_and_objects.hpp
@@ -11,8 +11,8 @@ public:
     [[nodiscard]] auto owner() const -> const std::string&;
     [[nodiscard]] auto balance() const -> double;
 
-    void deposit(double amount);
-    auto withdraw(double amount) -> bool;
+    void deposit(double amount) pre(amount > 0);
+    auto withdraw(double amount) -> bool pre(amount > 0);
 
 private:
     std::string owner_;
diff --git a/modules/06_oop_basics/src/classes_and_objects.cpp b/modules/06_oop_basics/src/classes_and_objects.cpp
index 18e3da1..80f0f41 100644
--- a/modules/06_oop_basics/src/classes_and_objects.cpp
+++ b/modules/06_oop_basics/src/classes_and_objects.cpp
@@ -2,20 +2,23 @@
 
 namespace oop {
 
-BankAccount::BankAccount(std::string owner, double balance)
+BankAccount::BankAccount(std::string owner, const double balance)
     : owner_(std::move(owner)), balance_(balance) {}
 
 auto BankAccount::owner() const -> const std::string& { return owner_; }
 auto BankAccount::balance() const -> double { return balance_; }
 
-void BankAccount::deposit(double amount) {
-    // TODO: Add amount when positive
-    (void)amount;
+void BankAccount::deposit(const double amount)
+{
+    this->balance_ += amount;
 }
 
-auto BankAccount::withdraw(double amount) -> bool {
-    // TODO: Return false if insufficient funds, else subtract and return true
-    (void)amount;
+auto BankAccount::withdraw(const double amount) -> bool
+{
+    if (this->balance_ >= amount) {
+        this->balance_ -= amount;
+        return true;
+    }
     return false;
 }
 
diff --git a/modules/06_oop_basics/test/classes_and_objects_test.cpp b/modules/06_oop_basics/test/classes_and_objects_test.cpp
index cd1d28c..fe82686 100644
--- a/modules/06_oop_basics/test/classes_and_objects_test.cpp
+++ b/modules/06_oop_basics/test/classes_and_objects_test.cpp
@@ -8,6 +8,8 @@ TEST(ClassesAndObjects, DepositAndWithdraw) {
     EXPECT_TRUE(account.withdraw(30.0));
     EXPECT_DOUBLE_EQ(account.balance(), 120.0);
     EXPECT_FALSE(account.withdraw(1000.0));
+    EXPECT_DEATH(account.withdraw(-10.0), "amount > 0");
+    EXPECT_DEATH(account.deposit(-10.0), "amount > 0");
 }
 
 TEST(ClassesAndObjects, OwnerName) {