Add serde support as a feature

Cargo.toml

@@ -15,4 +15,8 @@ travis-ci = { repository = "gngeorgiev/semver_rs", branch = "master" }
 [dependencies]
 lazy_static = "1.1"
 regex = "1"
-unicase = "2.3"
+unicase = "2.3"
+serde = { version = "1.0", features = ["derive"], optional = true }
+
+[features]
+default = []

src/builder.rs

@@ -2,6 +2,9 @@ use crate::error::Error;
 
 use std::marker::PhantomData;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 /// Allows building an [Options](crate::Options) instance.
 /// ## Example
 /// ```
@@ -44,6 +47,7 @@ impl OptionsBuilder {
 /// # Ok::<(), Error>(())
 /// ```
 #[derive(Default, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Options {
  /// Be more forgiving about not-quite-valid semver strings.
  /// Any resulting output will always be 100% strict compliant.

src/comparator.rs

@@ -12,6 +12,9 @@ use crate::version::Version;
 use std::cmp::Ordering;
 use std::fmt;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 /// ComparatorPair is a simple struct that can hold two comparators
 /// it knows how to format its Comparators
 #[derive(Debug)]
@@ -32,6 +35,7 @@ impl fmt::Display for ComparatorPair {
 /// A `Comparator` is composed of an [Operator](crate::operator::Operator) and a [Version](create::version::Version).
 /// Comparators are the building blocks of [Range](crate::range::Range)s
 #[derive(Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Comparator {
  pub operator: Operator,
  pub version: Version,

src/operator.rs

@@ -1,6 +1,10 @@
 use std::fmt;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 #[derive(PartialEq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum Operator {
  Gt,
  Lt,

src/range.rs

@@ -10,6 +10,9 @@ use crate::util::{is_any_version, match_at_index_str};
 use crate::version::Version;
 use std::borrow::Cow;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 /// A `version range` is a set of `comparators` which specify versions that satisfy the `range`.
 /// A comparator is composed of an operator and a version. The set of primitive operators is:
 ///
@@ -34,6 +37,7 @@ use std::borrow::Cow;
 ///
 /// The range `1.2.7 || >=1.2.9 <2.0.0` would match the versions `1.2.7`, `1.2.9`, and `1.4.6`, but not the versions `1.2.8` or `2.0.0`.
 #[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Range {
  pub(crate) comparators: Vec<Vec<Comparator>>,
 

src/version.rs

@@ -5,10 +5,14 @@ use crate::util::compare_identifiers;
 
 use std::{cmp::Ordering, fmt, str};
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 /// A `version` is described by the `v2.0.0` specification found at [semver](https://semver.org/).
 ///
 /// A leading `=` or `v` character is stripped off and ignored.
 #[derive(Default, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Version {
  pub major: i32,
  pub minor: i32,