// try_from_into.rs // // TryFrom is a simple and safe type conversion that may fail in a controlled way under some circumstances. // Basically, this is the same as From. The main difference is that this should return a Result type // instead of the target type itself. // You can read more about it at https://doc.rust-lang.org/std/convert/trait.TryFrom.html // // Your task is to complete this implementation // and return an Ok result of inner type Color. // You need to create an implementation for a tuple of three integers, // an array of three integers and a slice of integers. // // Note that the implementation for tuple and array will be checked at compile time, // but the slice implementation needs to check the slice length! // Also note that correct RGB color values must be integers in the 0..=255 range. // // If you need help, open the corresponding README.md or run: rustlings hint try_from_into // I AM NOT DONE use std::convert::{TryFrom, TryInto}; use std::error; #[derive(Debug, PartialEq)] struct Color { red: u8, green: u8, blue: u8, } // Tuple implementation impl TryFrom<(i16, i16, i16)> for Color { type Error = Box; fn try_from(tuple: (i16, i16, i16)) -> Result {} } // Array implementation impl TryFrom<[i16; 3]> for Color { type Error = Box; fn try_from(arr: [i16; 3]) -> Result {} } // Slice implementation impl TryFrom<&[i16]> for Color { type Error = Box; fn try_from(slice: &[i16]) -> Result {} } fn main() { // Use the `from` function let c1 = Color::try_from((183, 65, 14)); println!("{:?}", c1); // Since From is implemented for Color, we should be able to use Into let c2: Result = [183, 65, 14].try_into(); println!("{:?}", c2); let v = vec![183, 65, 14]; // With slice we should use `from` function let c3 = Color::try_from(&v[..]); println!("{:?}", c3); // or take slice within round brackets and use Into let c4: Result = (&v[..]).try_into(); println!("{:?}", c4); } #[cfg(test)] mod tests { use super::*; #[test] fn test_tuple_out_of_range_positive() { assert!(Color::try_from((256, 1000, 10000)).is_err()); } #[test] fn test_tuple_out_of_range_negative() { assert!(Color::try_from((-1, -10, -256)).is_err()); } #[test] fn test_tuple_sum() { assert!(Color::try_from((-1, 255, 255)).is_err()); } #[test] fn test_tuple_correct() { let c: Result = (183, 65, 14).try_into(); assert!(c.is_ok()); assert_eq!( c.unwrap(), Color { red: 183, green: 65, blue: 14 } ); } #[test] fn test_array_out_of_range_positive() { let c: Result = [1000, 10000, 256].try_into(); assert!(c.is_err()); } #[test] fn test_array_out_of_range_negative() { let c: Result = [-10, -256, -1].try_into(); assert!(c.is_err()); } #[test] fn test_array_sum() { let c: Result = [-1, 255, 255].try_into(); assert!(c.is_err()); } #[test] fn test_array_correct() { let c: Result = [183, 65, 14].try_into(); assert!(c.is_ok()); assert_eq!( c.unwrap(), Color { red: 183, green: 65, blue: 14 } ); } #[test] fn test_slice_out_of_range_positive() { let arr = [10000, 256, 1000]; assert!(Color::try_from(&arr[..]).is_err()); } #[test] fn test_slice_out_of_range_negative() { let arr = [-256, -1, -10]; assert!(Color::try_from(&arr[..]).is_err()); } #[test] fn test_slice_sum() { let arr = [-1, 255, 255]; assert!(Color::try_from(&arr[..]).is_err()); } #[test] fn test_slice_correct() { let v = vec![183, 65, 14]; let c: Result = Color::try_from(&v[..]); assert!(c.is_ok()); assert_eq!( c.unwrap(), Color { red: 183, green: 65, blue: 14 } ); } #[test] fn test_slice_excess_length() { let v = vec![0, 0, 0, 0]; assert!(Color::try_from(&v[..]).is_err()); } #[test] fn test_slice_insufficient_length() { let v = vec![0, 0]; assert!(Color::try_from(&v[..]).is_err()); } }