optimized unpack from slice: no more copying to vec

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bipack_ru"
-version = "0.3.2"
+version = "0.3.3"
 edition = "2021"
 license = "Apache-2.0"
 description = "binary size-effective format used in Divan smart contracts, wasm bindings, network protocols, etc."

src/bipack_source.rs

@@ -167,7 +167,7 @@ pub struct SliceSource<'a> {
 }
 
 impl<'a> SliceSource<'a> {
-    pub fn from(src: &'a [u8]) -> SliceSource {
+    pub fn from(src: &'a [u8]) -> SliceSource<'a> {
         SliceSource { data: src, position: 0 }
     }
 }

src/de.rs

@@ -2,23 +2,21 @@ use serde::de::{self, DeserializeSeed, IntoDeserializer, MapAccess, SeqAccess, V
 use serde::de::value::U32Deserializer;
 use serde::Deserialize;
 
-use crate::bipack_source::{BipackSource, VecSource};
+use crate::bipack_source::{BipackSource, SliceSource};
 use crate::error::{Error, Result};
 
-pub struct Deserializer {
+pub struct Deserializer<T: BipackSource> {
     // This string starts with the input data and characters are truncated off
     // the beginning as data is parsed.
-    input: VecSource,
+    input: T,
 }
 
 pub fn from_bytes<'de, T: Deserialize<'de>>(source: &[u8]) -> Result<T> {
-    let mut des = Deserializer { input: VecSource::from(source.to_vec()) };
+    let mut des = Deserializer { input: SliceSource::from(&source) };
     T::deserialize(&mut des)
 }
 
-impl Deserializer {}
-
-impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer {
+impl<'de, 'a,  T: BipackSource> de::Deserializer<'de> for &'a mut Deserializer<T> {
     type Error = Error;
 
     fn deserialize_any<V>(self, visitor: V) -> std::result::Result<V::Value, Self::Error> where V: Visitor<'de> {
@@ -163,7 +161,7 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer {
     }
 }
 
-impl<'de, 'a> serde::de::EnumAccess<'de> for &'a mut Deserializer {
+impl<'de, 'a, T: BipackSource> serde::de::EnumAccess<'de> for &'a mut Deserializer<T> {
     type Error = Error;
     type Variant = Self;
 
@@ -177,7 +175,7 @@ impl<'de, 'a> serde::de::EnumAccess<'de> for &'a mut Deserializer {
     }
 }
 
-impl<'de, 'a> serde::de::VariantAccess<'de> for &'a mut Deserializer {
+impl<'de, 'a, T: BipackSource> serde::de::VariantAccess<'de> for &'a mut Deserializer<T> {
     type Error = Error;
 
     #[inline]
@@ -206,13 +204,13 @@ impl<'de, 'a> serde::de::VariantAccess<'de> for &'a mut Deserializer {
 }
 
 
-struct SimpleSeq<'a> {
-    de: &'a mut Deserializer,
+struct SimpleSeq<'a,  T: BipackSource> {
+    de: &'a mut Deserializer<T>,
     size: usize,
 }
 
-impl<'a> SimpleSeq<'a> {
-    fn new(de: &'a mut Deserializer, size: usize) -> Self {
+impl<'a, T: BipackSource> SimpleSeq<'a, T> {
+    fn new(de: &'a mut Deserializer<T>, size: usize) -> Self {
         SimpleSeq {
             de,
             size: size,
@@ -222,12 +220,12 @@ impl<'a> SimpleSeq<'a> {
 
 // `SeqAccess` is provided to the `Visitor` to give it the ability to iterate
 // through elements of the sequence.
-impl<'de, 'a> SeqAccess<'de> for SimpleSeq<'a> {
+impl<'de, 'a, T: BipackSource> SeqAccess<'de> for SimpleSeq<'a, T> {
     type Error = Error;
 
-    fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
+    fn next_element_seed<S>(&mut self, seed: S) -> Result<Option<S::Value>>
         where
-            T: DeserializeSeed<'de>,
+            S: DeserializeSeed<'de>,
     {
         if self.size < 1 {
             return Ok(None);
@@ -238,12 +236,12 @@ impl<'de, 'a> SeqAccess<'de> for SimpleSeq<'a> {
 }
 
 
-struct SimpleMap<'a> {
-    de: &'a mut Deserializer,
+struct SimpleMap<'a,  T: BipackSource> {
+    de: &'a mut Deserializer<T>,
     size: usize,
 }
 
-impl<'de, 'a> MapAccess<'de> for SimpleMap<'a> {
+impl<'de, 'a, T: BipackSource> MapAccess<'de> for SimpleMap<'a,T> {
     type Error = Error;
 
     fn next_key_seed<K>(&mut self, seed: K) -> std::result::Result<Option<K::Value>, Self::Error> where K: DeserializeSeed<'de> {