Update to 2021 edition

Cargo.toml

@@ -10,7 +10,7 @@ categories = ["date-and-time"]
 readme = "README.md"
 license = "MIT/Apache-2.0"
 exclude = ["/ci/*"]
-edition = "2018"
+edition = "2021"
 rust-version = "1.56.0"
 
 [lib]

src/format/parsed.rs

@@ -4,8 +4,6 @@
 //! A collection of parsed date and time items.
 //! They can be constructed incrementally while being checked for consistency.
 
-use core::convert::TryFrom;
-
 use super::{ParseResult, IMPOSSIBLE, NOT_ENOUGH, OUT_OF_RANGE};
 use crate::naive::{NaiveDate, NaiveDateTime, NaiveTime};
 use crate::offset::{FixedOffset, LocalResult, Offset, TimeZone};

src/month.rs

@@ -1,4 +1,4 @@
-use core::{convert::TryFrom, fmt};
+use core::fmt;
 
 #[cfg(feature = "rkyv")]
 use rkyv::{Archive, Deserialize, Serialize};
@@ -12,7 +12,6 @@ use crate::OutOfRange;
 ///
 /// It is possible to convert from a date to a month independently
 /// ```
-/// # use std::convert::TryFrom;
 /// use chrono::prelude::*;
 /// let date = Utc.with_ymd_and_hms(2019, 10, 28, 9, 10, 11).unwrap();
 /// // `2019-10-28T09:10:11Z`
@@ -349,8 +348,6 @@ mod month_serde {
 
 #[cfg(test)]
 mod tests {
-    use core::convert::TryFrom;
-
     use super::Month;
     use crate::{Datelike, OutOfRange, TimeZone, Utc};
 

src/naive/date.rs

@@ -5,7 +5,6 @@
 
 #[cfg(any(feature = "alloc", feature = "std", test))]
 use core::borrow::Borrow;
-use core::convert::TryFrom;
 use core::ops::{Add, AddAssign, RangeInclusive, Sub, SubAssign};
 use core::{fmt, str};
 
@@ -2284,10 +2283,7 @@ mod tests {
     };
     use crate::oldtime::Duration;
     use crate::{Datelike, Weekday};
-    use std::{
-        convert::{TryFrom, TryInto},
-        i32, u32,
-    };
+    use std::{i32, u32};
 
     #[test]
     fn diff_months() {

src/naive/datetime/mod.rs

@@ -5,7 +5,6 @@
 
 #[cfg(any(feature = "alloc", feature = "std", test))]
 use core::borrow::Borrow;
-use core::convert::TryFrom;
 use core::fmt::Write;
 use core::ops::{Add, AddAssign, Sub, SubAssign};
 use core::{fmt, str};

src/naive/internals.rs

@@ -504,7 +504,6 @@ const fn weekday_from_u32_mod7(n: u32) -> Weekday {
 
 #[cfg(test)]
 mod tests {
-    use std::convert::TryFrom;
     use std::u32;
 
     use super::weekday_from_u32_mod7;

src/weekday.rs

@@ -1,4 +1,4 @@
-use core::{convert::TryFrom, fmt};
+use core::fmt;
 
 #[cfg(feature = "rkyv")]
 use rkyv::{Archive, Deserialize, Serialize};
@@ -14,7 +14,6 @@ use crate::OutOfRange;
 /// # Example
 /// ```
 /// use chrono::Weekday;
-/// use std::convert::TryFrom;
 ///
 /// let monday = "Monday".parse::<Weekday>().unwrap();
 /// assert_eq!(monday, Weekday::Mon);
@@ -233,7 +232,6 @@ impl fmt::Debug for ParseWeekdayError {
 #[cfg(test)]
 mod tests {
     use super::Weekday;
-    use std::convert::TryFrom;
 
     #[test]
     fn test_num_days_from() {