24: Add solutions for section "conversions".

Dependencies

• [2] H6XH45OP 0

Change contents

• edit in exercises/conversions/using_as.rs at line 7
  [2.145160]→[2.145160:145178](∅→∅)
  −

  − // I AM NOT DONE
• replacement in exercises/conversions/using_as.rs at line 10
  [2.145270]→[2.145270:145295](∅→∅)
  − total / values.len()
  [2.145270]

  [2.145295]
  + total / values.len() as f64
• replacement in exercises/conversions/try_from_into.rs at line 5
  [2.145938]→[2.145938:145992](∅→∅)
  − use std::convert::{TryFrom, TryInto};

  − use std::error;
  [2.145938]

  [2.145992]
  + use std::{convert::{TryFrom, TryInto}, error, fmt};
• edit in exercises/conversions/try_from_into.rs at line 13
  [2.146080]→[2.146080:146098](∅→∅)
  −

  − // I AM NOT DONE
• replacement in exercises/conversions/try_from_into.rs at line 26
  [2.146663]→[2.146663:146735](∅→∅)
  − fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {}
  [2.146663]

  [2.146735]
  + fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {

  + Ok(Color {

  + red: u8::try_from(tuple.0)?,

  + green: u8::try_from(tuple.1)?,

  + blue: u8::try_from(tuple.2)?

  + })

  + }
• replacement in exercises/conversions/try_from_into.rs at line 38
  [2.146837]→[2.146837:146900](∅→∅)
  − fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {}
  [2.146837]

  [2.146900]
  + fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {

  + Ok(Color {

  + red: u8::try_from(arr[0])?,

  + green: u8::try_from(arr[1])?,

  + blue: u8::try_from(arr[2])?

  + })

  + }
• edit in exercises/conversions/try_from_into.rs at line 46
  [2.146902]

  [2.146902]
  +

  + #[derive(Debug, Clone)]

  + struct IncorrectSliceLength;
• edit in exercises/conversions/try_from_into.rs at line 50
  [2.146903]

  [2.146903]
  + impl fmt::Display for IncorrectSliceLength {

  + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {

  + write!(f, "Incorrect slice length.")

  + }

  + }

  +

  + impl error::Error for IncorrectSliceLength {}

  +
• replacement in exercises/conversions/try_from_into.rs at line 61
  [2.147000]→[2.147000:147063](∅→∅)
  − fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {}
  [2.147000]

  [2.147063]
  + fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {

  + if slice.len() == 3 {

  + Ok(Color {

  + red: u8::try_from(slice[0])?,

  + green: u8::try_from(slice[1])?,

  + blue: u8::try_from(slice[2])?

  + })

  + } else { Err(Box::new(IncorrectSliceLength)) }

  + }
• replacement in exercises/conversions/from_str.rs at line 5
  [2.150438]→[2.150438:150477](∅→∅)
  − use std::error;

  − use std::str::FromStr;
  [2.150438]

  [2.150477]
  + use std::{error, str::FromStr, fmt};
• edit in exercises/conversions/from_str.rs at line 13
  [2.150548]→[2.150548:150566](∅→∅)
  − // I AM NOT DONE

  −
• edit in exercises/conversions/from_str.rs at line 23
  [2.151184]

  [2.151184]
  + #[derive(Debug, Clone)]

  + struct InvalidInput;

  +

  + impl fmt::Display for InvalidInput {

  + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {

  + write!(f, "Could not parse input.")

  + }

  + }

  +

  + impl error::Error for InvalidInput {}

  +
• edit in exercises/conversions/from_str.rs at line 37
  [2.151304]

  [2.151304]
  + let v: Vec<&str> = s.split(',').collect();

  + if v.len() != 2 || v[0].is_empty() {

  + Err(Box::new(InvalidInput))

  + } else {

  + Ok(Person {

  + name: v[0].to_string(),

  + age: v[1].parse::<usize>()?

  + })

  + }
• edit in exercises/conversions/from_into.rs at line 35
  [2.154035]→[2.154035:154053](∅→∅)
  −

  − // I AM NOT DONE
• edit in exercises/conversions/from_into.rs at line 38
  [2.154116]

  [2.154116]
  + let mut s = s.split(',');

  +

  + if let (Some(name), Some(age), None) = (s.next(), s.next(), s.next()) {

  + if let (false, Ok(age)) = (name.is_empty(), age.parse()) {

  + return Person {

  + name: String::from(name),

  + age,

  + };

  + }

  + }

  +

  + Person::default()
• edit in exercises/conversions/as_ref_mut.rs at line 4
  [2.156741]→[2.156741:156759](∅→∅)
  −

  − // I AM NOT DONE
• replacement in exercises/conversions/as_ref_mut.rs at line 7
  [2.156883]→[2.156883:156921](∅→∅)
  − fn byte_counter<T>(arg: T) -> usize {
  [2.156883]

  [2.156921]
  + fn byte_counter<T: AsRef<str>>(arg: T) -> usize {
• replacement in exercises/conversions/as_ref_mut.rs at line 13
  [2.157081]→[2.157081:157119](∅→∅)
  − fn char_counter<T>(arg: T) -> usize {
  [2.157081]

  [2.157119]
  + fn char_counter<T: AsRef<str>>(arg: T) -> usize {