Simplify Marker match by reusing discriminant

Author: kornelski

rmp/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rmp"
-version = "0.8.13"
+version = "0.8.14"
 authors = ["Evgeny Safronov <division494@gmail.com>"]
 license = "MIT"
 description = "Pure Rust MessagePack serialization implementation"

rmp/src/marker.rs

@@ -4,12 +4,26 @@ const FIXMAP_SIZE   : u8 = 0x0f;
 
 /// Format markers.
 #[derive(Clone, Copy, Debug, PartialEq)]
+#[repr(u8)]
 pub enum Marker {
-    FixPos(u8),
-    FixNeg(i8),
-    Null,
-    True,
+    FixPos(u8) = 0x00,
+    FixNeg(i8) = 0xe0,
+    FixMap(u8) = 0x80,
+    FixArray(u8) = 0x90,
+    FixStr(u8) = 0xa0,
+    Null = 0xc0,
+    // Marked in MessagePack spec as never used.
+    Reserved,
     False,
+    True,
+    Bin8,
+    Bin16,
+    Bin32,
+    Ext8,
+    Ext16,
+    Ext32,
+    F32,
+    F64,
     U8,
     U16,
     U32,
@@ -18,35 +32,24 @@ pub enum Marker {
     I16,
     I32,
     I64,
-    F32,
-    F64,
-    FixStr(u8),
+    FixExt1,
+    FixExt2,
+    FixExt4,
+    FixExt8,
+    FixExt16,
     Str8,
     Str16,
     Str32,
-    Bin8,
-    Bin16,
-    Bin32,
-    FixArray(u8),
     Array16,
     Array32,
-    FixMap(u8),
     Map16,
     Map32,
-    FixExt1,
-    FixExt2,
-    FixExt4,
-    FixExt8,
-    FixExt16,
-    Ext8,
-    Ext16,
-    Ext32,
-    Reserved,
 }
 
 impl Marker {
     /// Construct a msgpack marker from a single byte.
     #[must_use]
+    #[inline]
     pub fn from_u8(n: u8) -> Marker {
         match n {
             0x00 ..= 0x7f => Marker::FixPos(n),
@@ -91,7 +94,9 @@ impl Marker {
     }
 
     /// Converts a marker object into a single-byte representation.
-    #[must_use] pub fn to_u8(&self) -> u8 {
+    #[must_use]
+    #[inline]
+    pub fn to_u8(&self) -> u8 {
         match *self {
             Marker::FixPos(val)   => val,
             Marker::FixNeg(val)   => val as u8,
@@ -146,14 +151,14 @@ impl Marker {
 }
 
 impl From<u8> for Marker {
-    #[inline]
+    #[inline(always)]
     fn from(val: u8) -> Marker {
         Marker::from_u8(val)
     }
 }
 
 impl From<Marker> for u8 {
-    #[inline]
+    #[inline(always)]
     fn from(val: Marker) -> Self {
         val.to_u8()
     }