Key Concepts:

• Ownership: In Mojo, each value has a single "owner" variable responsible for its lifecycle. When the owner goes out, the value is automatically deallocated. This prevents "use-after-free", "double free", or "memory leak" errors.
• Borrowing: Mojo allows sharing values without transferring ownership through borrowing, enabling other parts of the code to read or even modify (with restrictions) the value.
• Borrow Checker: A compiler feature in Mojo that enforces the rules of ownership and borrowing, ensuring memory safety.

Argument Conventions:

• borrowed: An immutable reference. The function can read but not modify the original value.
• inout: A mutable reference. The function can both read and modify the original value.
• owned: The function takes ownership of the value. This implies exclusive access and responsibility for deallocating the value.

Prerequisites: Understanding of basic programming concepts like functions, variables, and memory management is essential. Familiarity with concepts from languages like Rust or C++ regarding ownership and memory safety would be beneficial.

Code Example Explained:

mojoCopy code
fn add(inout x: Int, borrowed y: Int):
    x += y

fn main():
    var a = 1
    var b = 2
    add(a, b)
    print(a)  # Prints 3

• fn add: A function that takes two parameters: x, a mutable reference, and y, an immutable reference.
• inout x: Int: x can be read and modified inside add.
• borrowed y: Int: y can only be read, not modified.
• x += y: The value of x is increased by y, demonstrating mutation.
• var a = 1: Declares an integer a with a value of 1.
• add(a, b): Calls add, passing a as a mutable reference (implicitly) and b as an immutable reference.
• print(a): After add is called, a is modified to 3, demonstrating the effect of the inout parameter.

Potential Questions:

• Q: What happens if I try to modify a borrowed parameter?