smart_pointer_test

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Filename: smart_pointer_test.py
# Version: 1.0.0
# Author: Jeoi Reqi

"""
:: Python Smart Pointer Test ::

Description:
    - This script demonstrates smart pointer behavior through test scenarios.
    - It includes scenarios for moving null pointers and moving non-null pointers.

Requirements:
    - Python 3.x

Functions:
    - move_constructor_or_get(): Executes test scenarios to demonstrate smart pointer behavior.

Usage:
    - Run the script, and it will execute the test scenarios.
    - Review the output to observe the behavior of smart pointers.

Additional Notes:
    - In the Python version, UniquePtr is implemented as a simple class that wraps a pointer.
    - It doesn't perform manual memory management due to Python's automatic garbage collection.
    - However, it serves the same purpose conceptually, providing a way to manage ownership of objects.
"""

class UniquePtr:
    """A simple smart pointer class managing ownership of a pointer."""

    def __init__(self, ptr):
        """Initialize the UniquePtr with a pointer."""
        self.ptr = ptr

    def __del__(self):
        """Destructor to clean up the pointer."""
        del self.ptr

class Spy:
    """A class used for tracking copy operations and deletions."""

    def __init__(self, is_deleted, copy_count):
        """Initialize Spy object with deletion status and copy count."""
        self.is_deleted = is_deleted
        self.copy_count = copy_count

    def __del__(self):
        """Destructor to mark the object as deleted."""
        self.is_deleted = True

def line():
    """
    Prints a line of dashes for visual separation.
    """
    print("-" * 67)

def move_constructor_or_get():
    """Tests scenarios to demonstrate smart pointer behavior."""
    line()
    print("\n  :: [Testing scenarios to demonstrate smart pointer behavior] ::\n")

    # Scenario 1: Moving null pointers
    line()
    print("Scenario 1: \t[Moving null pointers]\n")
    print("- Creating a UniquePtr with a null pointer...")
    uptr = UniquePtr(None)
    uptr2 = UniquePtr(uptr.ptr)
    print("- Verifying that both pointers are null...")
    assert uptr.ptr is None
    assert uptr2.ptr is None
    print("\n\t\t[Both pointers are null as expected]")
    print("\nScenario 1: \t[Moving null pointers]\t\t\t  [Passed!]")

    # Scenario 2: Moving non-null pointers
    line()
    print("Scenario 2: \t[Moving non-null pointers]\n")
    print("- Creating a Spy object and wrapping it in a UniquePtr...")
    copy_count = 0
    is_deleted = False
    ptr = Spy(is_deleted, copy_count)
    uptr = UniquePtr(ptr)
    print("- Moving the UniquePtr to another UniquePtr...")
    uptr2 = UniquePtr(uptr.ptr)
    print("- Verifying ownership transfer and copy count...")
    assert uptr.ptr is ptr
    assert uptr2.ptr is ptr
    assert copy_count == 0
    print("\n\t\t[Ownership transferred successfully]")
    print("\t\t[Copy count is as expected]")
    print("\nScenario 2: \t[Moving non-null pointers]\t\t  [Passed!]")

if __name__ == "__main__":
    move_constructor_or_get()
    line()
    print("\n\t\tAll test scenarios passed successfully.\n\t\t   Exiting Program...    GoodBye!\n")
    line()