stdbool

---

1. Simple True/False Check

bool is_valid = true;
if (is_valid) {
  // Do something
}

2. Function Parameter Validation

bool is_positive(int number) {
  return number > 0;
}

3. Conditional Compilation

#ifdef DEBUG
  // Debug code
#else
  // Release code
#endif

4. Loop Control

while (is_running) {
  // Do something
}

5. Error Handling

if (error_code == 0) {
  // No error
} else {
  // Error occurred
}

6. Boolean Algebra

bool a = true, b = false;
bool result = a && b; // False

7. Tristate Logic

enum Tristate { True, False, Unknown };
Tristate state = Unknown;

8. Bit Manipulation

bool bit_set = (flags & 0x01) != 0;

9. Data Structure Flags

struct Node {
  bool is_leaf;
};

10. Class Member Variables

class MyClass {
  private:
    bool is_initialized;
};

11. Input Validation

int input;
while (!(std::cin >> input)) {
  std::cout << "Invalid input. Please enter an integer: ";
}

12. Function Return Values

bool is_prime(int number) {
  // Check for primality
  return true;
}

13. Event Handling

class MyEventHandler {
  public:
    void on_click() {
      is_clicked = true;
    }
    bool is_clicked = false;
};

14. State Machine

enum State {
  Start,
  Idle,
  Running,
  Finished
};
State current_state = Start;

15. Data Stream Validation

std::ifstream file;
file.open("data.txt");
if (!file.is_open()) {
  // Error: File could not be opened
}

16. Property Accessors

class MyClass {
  public:
    bool get_is_valid() const {
      return is_valid;
    }
    void set_is_valid(bool new_value) {
      is_valid = new_value;
    }
  private:
    bool is_valid;
};

17. Function Overloading

void print(int number) {
  std::cout << number;
}

void print(bool value) {
  std::cout << (value ? "true" : "false");
}

18. Template Argument Deduction

template <typename T>
void my_function(T value) {
  bool is_true = static_cast<bool>(value);
}

19. Type Conversion

int number = true; // Converts true to 1

20. Bitwise Operations

bool a = true, b = false;
bool result = a | b; // True

21. Logical Negation

bool is_not_valid = !is_valid;

22. Conditional Operator

bool a = true;
int result = (a ? 1 : 0); // result is 1

23. Function Invocation with Boolean Parameters

void my_function(bool is_enabled) {
  // Do something based on is_enabled
}

24. Data Structure Comparisons

std::vector<int> a, b;
bool is_equal = (a == b);

25. Range Check

int index = 5;
int array_size = 10;
bool is_within_range = (index >= 0 && index < array_size);

26. String Comparison

std::string a = "hello", b = "world";
bool is_same_string = (a == b);

27. File Existence Check

std::ifstream file("myfile.txt");
bool file_exists = file.is_open();

28. Array Subscript Validation

int array[5];
bool is_valid_index = (index >= 0 && index < 5);

29. Pointer Dereferencing Check

int* pointer = nullptr;
bool is_valid_pointer = (pointer != nullptr);

30. Function Return Type

bool my_function() {
  // Do something
  return true;
}

31. Loop Termination Condition

for (auto it = collection.begin(); it != collection.end(); ++it) {
  if (*it == target) {
    break;
  }
}

32. Collection Size Check

std::vector<int> vec;
bool is_empty = vec.empty();

33. User Input Confirmation

std::cout << "Are you sure you want to quit? (Y/N): ";
bool is_quitting = (std::cin.get() == 'Y');

34. Runtime Feature Control

#ifdef FEATURE_ENABLED
  // Feature is enabled
#else
  // Feature is disabled
#endif

35. Error Code Handling

enum ErrorCode {
  NoError,
  InvalidInput,
  OutOfMemory
};
bool handle_error(ErrorCode error_code) {
  // Handle the error
  return true;
}

36. Thread Synchronization

std::mutex lock;
bool is_locked = false;

37. Singleton Class Implementation

class Singleton {
  private:
    static bool is_initialized = false;
    static Singleton* instance = nullptr;
  public:
    static Singleton* get_instance() {
      if (!is_initialized) {
        instance = new Singleton();
        is_initialized = true;
      }
      return instance;
    }
};

38. Memory Pool Allocation

class MemoryPool {
  private:
    std::vector<bool> allocated;
  public:
    void* allocate() {
      for (size_t i = 0; i < allocated.size(); ++i) {
        if (!allocated[i]) {
          allocated[i] = true;
          return &pool[i];
        }
      }
      return nullptr;
    }
    void deallocate(void* ptr) {
      for (size_t i = 0; i < allocated.size(); ++i) {
        if (&pool[i] == ptr) {
          allocated[i] = false;
          return;
        }
      }
    }
  private:
    std::vector<char> pool;
};

39. State-Dependent Behavior

class MyClass {
  public:
    void set_state(bool new_state) {
      is_active = new_state;
    }
    void do_something() {
      if (is_active) {
        // Do something when active
      } else {
        // Do something when inactive
      }
    }
  private:
    bool is_active;
};

40. Thread-Safe Data Retrieval

std::atomic<bool> is_ready = false;
std::atomic<bool> is_fetched = false;
std::thread fetch_thread([&]() {
  // Fetch data
  is_ready.store(true);
});
void get_data() {
  while (!is_ready.load());
  // Access data
  is_fetched.store(true);
}

41. Data Structure Invalidation Check

class MyData {
  public:
    void invalidate() {
      is_invalid = true;
    }
    bool is_invalid = false;
};

42. Signal Handling

volatile sig_atomic_t is_running = true;
void signal_handler(int signal) {
  is_running = false;
}

43. Lazy Initialization

std::once_flag flag;
std::shared_ptr<MyClass> my_class;
void init_my_class() {
  my_class = std::make_shared<MyClass>();
}
std::shared_ptr<MyClass> get_my_class() {
  std::call_once(flag, init_my_class);
  return my_class;
}

44. Exception Handling

try {
  // Do something
} catch (const std::exception& e) {
  is_error = true;
}

45. Resource Management

class MyClass : public std::enable_shared_from_this<MyClass> {
  public:
    bool is_allocated = false;
    void allocate() {
      is_allocated = true;
    }
    void deallocate() {
      is_allocated = false;
    }
};

46. Thread-Safe Function Invocation

std::mutex lock;
bool is_function_done = false;
void my_function() {
  // Do something
  std::lock_guard<std::mutex> guard(lock);
  is_function_done = true;
}

47. Loop Optimization

bool is_valid = true;
for (auto it = collection.begin(); it != collection.end() && is_valid; ++it) {
  // Do something
}

48. Algorithm Short-Circuiting

std::vector<int> vec;
bool all_positive = true;
for (auto it = vec.begin(); it != vec.end() && all_positive; ++it) {
  if (*it < 0) {
    all_positive = false;
  }
}

49. Protocol Version Compatibility

#define PROTOCOL_VERSION 1
bool is_compatible(int version) {
  return version == PROTOCOL_VERSION;
}

50. Input Validation with Regular Expressions

std::regex email_regex("^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$");
bool is_valid_email(std::string email) {
  return std::regex_match(email, email_regex);
}