Implement Serialize for flexbuffer::Reader (#6635)

* Implement Serialize for flexbuffer::Reader

* bump version

* Remove use of experimantal or-patterns

* Remove more use of experimantal or-patterns

Co-authored-by: Casper Neo <cneo@google.com>

rust/flexbuffers/src/builder/map.rs

@@ -97,8 +97,7 @@ pub(super) fn sort_map_by_keys(values: &mut [Value], buffer: &[u8]) {
     // preferred over custom sorting or adding another dependency. By construction, this part
     // of the values stack must be alternating (key, value) pairs. The public API must not be
     // able to trigger the above debug_assets that protect this unsafe usage.
-    let pairs: &mut [[Value; 2]] =
-        unsafe { std::slice::from_raw_parts_mut(raw_pairs, pairs_len) };
+    let pairs: &mut [[Value; 2]] = unsafe { std::slice::from_raw_parts_mut(raw_pairs, pairs_len) };
     #[rustfmt::skip]
     pairs.sort_unstable_by(|[key1, _], [key2, _]| {
         if let Value::Key(a1) = *key1 {

rust/flexbuffers/src/builder/mod.rs

@@ -32,10 +32,11 @@ macro_rules! push_slice {
         fn $push_name<T, S>(&mut self, xs: S)
         where
             T: Into<$scalar> + Copy,
-            S: AsRef<[T]>
+            S: AsRef<[T]>,
         {
             let mut value = Value::$new_vec(xs.as_ref().len());
-            let mut width = xs.as_ref()
+            let mut width = xs
+                .as_ref()
                 .iter()
                 .map(|x| BitWidth::from((*x).into()))
                 .max()
@@ -56,7 +57,7 @@ macro_rules! push_slice {
             value.set_child_width_or_panic(width);
             self.values.push(value);
         }
-    }
+    };
 }
 macro_rules! push_indirect {
     ($push_name: ident, $scalar: ty, $Direct: ident, $Indirect: ident) => {
@@ -65,15 +66,13 @@ macro_rules! push_indirect {
             let child_width = x.width_or_child_width();
             let address = self.buffer.len();
             store_value(&mut self.buffer, x, child_width);
-            self.values.push(
-                Value::Reference {
-                    address,
-                    child_width,
-                    fxb_type: FlexBufferType::$Indirect,
-                }
-            );
+            self.values.push(Value::Reference {
+                address,
+                child_width,
+                fxb_type: FlexBufferType::$Indirect,
+            });
         }
-    }
+    };
 }
 
 bitflags! {

rust/flexbuffers/src/builder/ser.rs

@@ -36,6 +36,10 @@ impl FlexbufferSerializer {
     pub fn take_buffer(&mut self) -> Vec<u8> {
         self.builder.take_buffer()
     }
+    pub fn reset(&mut self) {
+        self.builder.reset();
+        self.nesting.clear();
+    }
     fn finish_if_not_nested(&mut self) -> Result<(), Error> {
         if self.nesting.is_empty() {
             assert_eq!(self.builder.values.len(), 1);