add serde support to Value

Cargo.toml

@@ -16,7 +16,7 @@ exclude = ["rfcs/**/*", "/.travis.yml", "/appveyor.yml"]
 build = "build.rs"
 
 [package.metadata.docs.rs]
-features = ["std", "serde", "kv_unstable_std", "kv_unstable_sval"]
+features = ["std", "serde", "kv_unstable_std", "kv_unstable_sval", "kv_unstable_serde"]
 
 [[test]]
 name = "filters"
@@ -48,6 +48,7 @@ std = []
 kv_unstable = ["value-bag"]
 kv_unstable_sval = ["kv_unstable", "value-bag/sval", "sval"]
 kv_unstable_std = ["std", "kv_unstable", "value-bag/error"]
+kv_unstable_serde = ["kv_unstable_std", "value-bag/serde", "serde"]
 
 [dependencies]
 cfg-if = "1.0"

src/kv/value.rs

@@ -7,6 +7,9 @@ extern crate value_bag;
 #[cfg(feature = "kv_unstable_sval")]
 extern crate sval;
 
+#[cfg(feature = "kv_unstable_serde")]
+extern crate serde;
+
 use self::value_bag::ValueBag;
 
 pub use kv::Error;
@@ -147,6 +150,17 @@ impl<'v> Value<'v> {
         }
     }
 
+    #[cfg(feature = "kv_unstable_serde")]
+    /// Get a value from a type implementing `serde::Serialize`.
+    pub fn capture_serde<T>(value: &'v T) -> Self
+    where
+        T: self::serde::Serialize + 'static,
+    {
+        Value {
+            inner: ValueBag::capture_serde1(value),
+        }
+    }
+
     /// Get a value from a type implementing `sval::value::Value`.
     #[cfg(feature = "kv_unstable_sval")]
     pub fn capture_sval<T>(value: &'v T) -> Self
@@ -178,6 +192,17 @@ impl<'v> Value<'v> {
         }
     }
 
+    /// Get a value from a type implementing `serde::Serialize`.
+    #[cfg(feature = "kv_unstable_serde")]
+    pub fn from_serde<T>(value: &'v T) -> Self
+    where
+        T: self::serde::Serialize,
+    {
+        Value {
+            inner: ValueBag::from_serde1(value),
+        }
+    }
+
     /// Get a value from a type implementing `sval::value::Value`.
     #[cfg(feature = "kv_unstable_sval")]
     pub fn from_sval<T>(value: &'v T) -> Self
@@ -261,6 +286,16 @@ impl ToValue for dyn std::error::Error + 'static {
     }
 }
 
+#[cfg(feature = "kv_unstable_serde")]
+impl<'v> self::serde::Serialize for Value<'v> {
+    fn serialize<S>(&self, s: S) -> Result<S::Ok, S::Error>
+    where
+        S: self::serde::Serializer,
+    {
+        self.inner.serialize(s)
+    }
+}
+
 #[cfg(feature = "kv_unstable_sval")]
 impl<'v> self::sval::value::Value for Value<'v> {
     fn stream(&self, stream: &mut self::sval::value::Stream) -> self::sval::value::Result {
@@ -485,6 +520,14 @@ pub(crate) mod tests {
         assert!(Value::from_dyn_error(&err).to_error().is_some());
     }
 
+    #[cfg(feature = "kv_unstable_serde")]
+    #[test]
+    fn test_capture_serde() {
+        assert_eq!(Some(42u64), Value::capture_serde(&42).to_u64());
+
+        assert_eq!(Some(42u64), Value::from_serde(&42).to_u64());
+    }
+
     #[cfg(feature = "kv_unstable_sval")]
     #[test]
     fn test_capture_sval() {