Make serde optional

Cargo.toml

@@ -4,6 +4,8 @@ version = "0.1.0"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[features]
+serde = ["dep:serde"]
 
 [dependencies]
-serde = { version = "1.0", features = ["derive"] }
+serde = { version = "1.0", features = ["derive"], optional = true }

src/datetime.rs

@@ -1,13 +1,16 @@
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 use {
     crate::{
         month::Month, weekday::Weekday, year::Year, zone::TimeZone, SECONDS_PER_DAY,
         SECONDS_PER_HOUR, SECONDS_PER_MINUTE,
     },
-    serde::{Deserialize, Serialize},
     std::{cmp, fmt},
 };
 
-#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[derive(Clone, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub struct DateTime {
     pub year: Year,
     pub month: Month,

src/lib.rs

@@ -8,6 +8,7 @@ pub(crate) mod year;
 pub(crate) mod zone;
 
 pub mod prelude;
+pub use datetime::DateTime;
 
 pub static SECONDS_PER_MINUTE: i64 = 60;
 pub static SECONDS_PER_HOUR: i64 = 60 * 60;

src/month.rs

@@ -1,12 +1,13 @@
-use std::str::FromStr;
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use {
     crate::{year::Year, SECONDS_PER_DAY},
-    serde::{Deserialize, Serialize},
-    std::{cmp, error, fmt},
+    std::{cmp, error, fmt, str},
 };
 
-#[derive(Clone, Copy, Debug, Deserialize, Serialize, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 #[repr(u8)]
 pub enum Month {
     Janurary = 1,
@@ -138,7 +139,7 @@ impl fmt::Display for Month {
     }
 }
 
-impl FromStr for Month {
+impl str::FromStr for Month {
     type Err = Error;
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {

src/prelude.rs

@@ -1,5 +1,4 @@
 pub use crate::{
-    datetime::DateTime,
     month::{Error as MonthError, Month},
     weekday::Weekday,
     year::Year,

src/weekday.rs

@@ -1,8 +1,10 @@
-use std::fmt;
-
+#[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
-#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
+use std::fmt;
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 #[repr(u8)]
 pub enum Weekday {
     Thursday,

src/year.rs

@@ -1,10 +1,13 @@
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 use {
     crate::SECONDS_PER_DAY,
-    serde::{Deserialize, Serialize},
     std::{cmp, fmt, num::ParseIntError, str::FromStr},
 };
 
-#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub enum Year {
     Normal(i32),
     Leap(i32),

src/zone.rs

@@ -1,10 +1,13 @@
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 use {
     crate::SECONDS_PER_HOUR,
-    serde::{Deserialize, Serialize},
     std::{error, fmt, str::FromStr},
 };
 
-#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub enum Sign {
     Positive,
     Negative,
@@ -23,7 +26,8 @@ impl fmt::Display for Sign {
     }
 }
 
-#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub enum TimeZone {
     Offset { sign: Sign, hours: u8, minutes: u8 },
     Utc,