Creating your own Result type

The task requires developing a custom Result type that will be used to pass the result of a function execution along with error information. Implement a structure Result<T, E>, where T is the data type in case of success, and E is the error type. Provide methods for creating successful results and error results, as well as methods for checking the state and retrieving nested values.

Requirements:

• Define a generic structure Result<T, E>.
• Implement constructors ok(value: T) -> Result<T, E> and err(error: E) -> Result<T, E>.
• Add methods is_ok() -> bool, is_err() -> bool.
• Implement methods unwrap() -> T (panics on error) and unwrap_err() -> E (panics on success).
• Optionally, you can add methods map, map_err, and other convenient functions.

Example usage (you can change variable names, but leave the code unchanged):

let success: Result<i32, &str> = Result::ok(42);
let failure: Result<i32, &str> = Result::err("error occurred");

assert!(success.is_ok());
assert!(!failure.is_ok());

let value = success.unwrap();
let err_msg = failure.unwrap_err();

This task is suitable for assessing skills in generics, error handling patterns, and basic API design principles.