diff --git a/Cargo.toml b/Cargo.toml
index 43c2b4e..ad23f6b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "bipack_ru"
-version = "0.3.3"
+version = "0.4.0"
 edition = "2021"
 license = "Apache-2.0"
 description = "binary size-effective format used in Divan smart contracts, wasm bindings, network protocols, etc."
diff --git a/README.md b/README.md
index 7f3e2b2..4e8c5c0 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,13 @@ pub struct DefinitelyBigEndian {
 }
 ```
 
+## Fixed or variable length arrays?
+
+When encoding  arrays, the rule is simple:
+
+- dynamic arrays (arrays, vectors, etc) are encoding with size, as variable-length
+- fixed-size arrays, like tuples `(1,2,3,4,5)`, or something like `[u32; 5]` are encoded as fixed-size entities.
+
 # Direct usage (no serde)
 
 The sample code (see `src/lib.rs` for more:)
diff --git a/src/bipack.rs b/src/bipack.rs
index 9f48d5c..512e94f 100644
--- a/src/bipack.rs
+++ b/src/bipack.rs
@@ -4,7 +4,7 @@ use crate::bipack_source::{BipackSource, Result};
 /// The trait to unpack to be used in serializer to come. Please don't use it, it is
 /// experimental.
 pub trait BiPackable {
-    fn bi_pack(self: &Self, sink: &mut impl BipackSink);
+    fn bi_pack(self: &Self, sink: &mut impl BipackSink)  -> Result<()>;
 }
 
 /// The trait need by [bipack()] macro and in the serializer to come, packs some
@@ -24,20 +24,20 @@ macro_rules! bipack {
     ( $( $e: expr),* ) => {{
         let mut result = Vec::new();
         $(
-            $e.bi_pack(&mut result);
+            $e.bi_pack(&mut result).unwrap();
         )*
         result
     }};
 }
 
 impl<T: IntoU64 + Copy> BiPackable for T {
-    fn bi_pack(self: &Self, sink: &mut impl BipackSink) {
+    fn bi_pack(self: &Self, sink: &mut impl BipackSink) -> Result<()> {
         sink.put_unsigned(self.into_u64())
     }
 }
 
 impl BiPackable for &str {
-    fn bi_pack(self: &Self, sink: &mut impl BipackSink) {
+    fn bi_pack(self: &Self, sink: &mut impl BipackSink)  -> Result<()> {
         sink.put_str(self)
     }
 }
diff --git a/src/bipack_sink.rs b/src/bipack_sink.rs
index 1fc08a9..c91611c 100644
--- a/src/bipack_sink.rs
+++ b/src/bipack_sink.rs
@@ -14,6 +14,7 @@
 
 use std::iter::Iterator;
 use std::usize;
+use crate::bipack_source::Result;
 
 const V0LIMIT: u64 = 1u64 << 6;
 const V1LIMIT: u64 = 1u64 << 14;
@@ -48,85 +49,89 @@ into_u64!(u8, u16, u32, usize, u64);
 /// sink you can create one that ignores extra data when overflow is detected and report it
 /// somehow, but for encoding it does not worth effort (data size could be estimated in advance).
 pub trait BipackSink {
-    fn put_u8(self: &mut Self, data: u8);
 
-    fn put_fixed_bytes(self: &mut Self, data: &[u8]) {
-        for b in data { self.put_u8(*b); }
+    fn put_u8(self: &mut Self, data: u8) -> Result<()>;
+
+    fn put_fixed_bytes(self: &mut Self, data: &[u8]) -> Result<()> {
+        for b in data { self.put_u8(*b)?; }
+        Ok(())
     }
 
-    fn put_var_bytes(self: &mut Self, data: &[u8]) {
-        self.put_unsigned(data.len());
-        self.put_fixed_bytes(data);
+    fn put_var_bytes(self: &mut Self, data: &[u8]) -> Result<()> {
+        self.put_unsigned(data.len())?;
+        self.put_fixed_bytes(data)
     }
 
-    fn put_str(self: &mut Self, str: &str) {
-        self.put_var_bytes(str.as_bytes());
+    fn put_str(self: &mut Self, str: &str) -> Result<()> {
+        self.put_var_bytes(str.as_bytes())
     }
 
-    fn put_u16(self: &mut Self, mut value: u16) {
+    fn put_u16(self: &mut Self, mut value: u16) -> Result<()>{
         let mut result = [0u8; 2];
         for i in (0..result.len()).rev() {
             result[i] = value as u8;
             value = value >> 8;
         }
-        self.put_fixed_bytes(&result);
+        self.put_fixed_bytes(&result)
     }
 
-    fn put_u32(self: &mut Self, mut value: u32) {
+    fn put_u32(self: &mut Self, mut value: u32) -> Result<()> {
         let mut result = [0u8; 4];
         for i in (0..result.len()).rev() {
             result[i] = value as u8;
             value = value >> 8;
         }
-        self.put_fixed_bytes(&result);
+        self.put_fixed_bytes(&result)
     }
-    fn put_u64(self: &mut Self, mut value: u64) {
+    fn put_u64(self: &mut Self, mut value: u64)  -> Result<()> {
         let mut result = [0u8; 8];
         for i in (0..result.len()).rev() {
             result[i] = value as u8;
             value = value >> 8;
         }
-        self.put_fixed_bytes(&result);
+        self.put_fixed_bytes(&result)
     }
 
-    fn put_i64(self: &mut Self, value: i64) {
+    fn put_i64(self: &mut Self, value: i64) -> Result<()> {
         self.put_u64(value as u64)
     }
-    fn put_i32(self: &mut Self, value: i32) {
+    fn put_i32(self: &mut Self, value: i32) -> Result<()> {
         self.put_u32(value as u32)
     }
-    fn put_i16(self: &mut Self, value: i16) {
+    fn put_i16(self: &mut Self, value: i16) -> Result<()> {
         self.put_u16(value as u16)
     }
-    fn put_i8(self: &mut Self, value: i8) {
+    fn put_i8(self: &mut Self, value: i8)  -> Result<()>{
         self.put_u8(value as u8)
     }
 
     /// Put unsigned value to compressed variable-length format, `Smartint` in the bipack
     /// terms. This format is used to store size of variable-length binaries and strings.
     /// Use [crate::bipack_source::BipackSource::get_unsigned] to unpack it.
-    fn put_unsigned<T: IntoU64>(self: &mut Self, number: T) {
+    fn put_unsigned<T: IntoU64>(self: &mut Self, number: T)  -> Result<()> {
         let value = number.into_u64();
-        let mut encode_seq = |ty: u8, bytes: &[u64]| {
-            if bytes.len() == 0 { self.put_u8(0); } else {
+        let mut encode_seq = |ty: u8, bytes: &[u64]| -> Result<()> {
+            if bytes.len() == 0 { self.put_u8(0)?; } else {
                 if bytes[0] as u64 > V0LIMIT { panic!("first byte is too big (internal error)"); }
-                self.put_u8((ty & 0x03) | ((bytes[0] as u8) << 2));
+                self.put_u8((ty & 0x03) | ((bytes[0] as u8) << 2))?;
                 for i in 1..bytes.len() {
-                    self.put_u8(bytes[i] as u8);
+                    self.put_u8(bytes[i] as u8)?;
                 }
             }
+            Ok(())
         };
 
         if value < V0LIMIT {
-            encode_seq(0, &[value]);
+            encode_seq(0, &[value])?;
         } else if value < V1LIMIT {
-            encode_seq(1, &[value & 0x3F, value >> 6]);
+            encode_seq(1, &[value & 0x3F, value >> 6])?;
         } else if value < V2LIMIT {
-            encode_seq(2, &[value & 0x3f, value >> 6, value >> 14]);
+            encode_seq(2, &[value & 0x3f, value >> 6, value >> 14])?;
         } else {
-            encode_seq(3, &[value & 0x3f, value >> 6, value >> 14]);
-            self.put_var_unsigned(value >> 22);
+            encode_seq(3, &[value & 0x3f, value >> 6, value >> 14])?;
+            self.put_var_unsigned(value >> 22)?;
         }
+        Ok(())
     }
 
     /// Put variable-length encoded integer value. it is packed just like variable-length
@@ -135,30 +140,35 @@ pub trait BipackSink {
     ///
     /// Note that for really big number using [BipackSink::put_i64] could be more effective
     /// than the variable-length.
-    fn put_signed(self: &mut Self, val: i64) {
+    fn put_signed(self: &mut Self, val: i64) -> Result<()> {
         let (neg, val) = if val < 0 { (1, -val) } else { (0, val) };
-        self.put_unsigned( (neg as u64) | ((val as u64) << 1) );
+        self.put_unsigned( (neg as u64) | ((val as u64) << 1) )
     }
 
-    fn put_var_unsigned(self: &mut Self, value: u64) {
+    fn put_var_unsigned(self: &mut Self, value: u64)  -> Result<()>{
         let mut rest = value;
         loop {
             let x = rest & 127;
             rest = rest >> 7;
             if rest > 0 {
-                self.put_u8((x | 0x80) as u8);
+                self.put_u8((x | 0x80) as u8)?;
             } else {
-                self.put_u8(x as u8)
+                self.put_u8(x as u8)?
             }
             if rest == 0 { break; }
         }
+        Ok(())
     }
 }
 
 
 impl BipackSink for Vec<u8> {
-    fn put_u8(self: &mut Self, data: u8) {
+    fn put_u8(self: &mut Self, data: u8) -> Result<()> {
         self.push(data);
+        Ok(())
     }
 }
 
+
+
+
diff --git a/src/bipack_source.rs b/src/bipack_source.rs
index 22383e5..f946599 100644
--- a/src/bipack_source.rs
+++ b/src/bipack_source.rs
@@ -20,10 +20,19 @@ use crate::bipack_source::BipackError::NoDataError;
 pub type Result<T> = std::result::Result<T, BipackError>;
 
 /// There is not enought data to fulfill the request
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
+#[non_exhaustive]
 pub enum BipackError {
     NoDataError,
     BadEncoding(FromUtf8Error),
+    BufferOverflow,
+    Message(String),
+    BadFormat(String),
+    Eof,
+    ExtraBytes,
+    NotSupported,
+    NotImplemented,
+    NotPossible
 }
 
 impl std::error::Error for BipackError {}
diff --git a/src/buffer_sink.rs b/src/buffer_sink.rs
new file mode 100644
index 0000000..95113a2
--- /dev/null
+++ b/src/buffer_sink.rs
@@ -0,0 +1,26 @@
+use crate::bipack_sink::BipackSink;
+use crate::bipack_source::BipackError;
+use crate::bipack_source::Result;
+
+pub struct BufferSink<'a> {
+    pub buffer: & 'a mut [u8],
+    pub pos: usize
+}
+
+impl<'a> BufferSink<'a> {
+    pub fn result_slice(self) -> & 'a [u8] {
+        &self.buffer[0..self.pos]
+    }
+}
+
+impl<'a> BipackSink for BufferSink<'a> {
+    fn put_u8(self: &mut Self, data: u8) -> Result<()> {
+        if self.pos >= self.buffer.len() {
+            Err(BipackError::BufferOverflow)
+        } else {
+            self.buffer[self.pos] = data;
+            self.pos+=1;
+            Ok(())
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/de.rs b/src/de.rs
index 631cfce..5861962 100644
--- a/src/de.rs
+++ b/src/de.rs
@@ -2,8 +2,8 @@ use serde::de::{self, DeserializeSeed, IntoDeserializer, MapAccess, SeqAccess, V
 use serde::de::value::U32Deserializer;
 use serde::Deserialize;
 
-use crate::bipack_source::{BipackSource, SliceSource};
-use crate::error::{Error, Result};
+use crate::bipack_source::{BipackError, BipackSource, SliceSource};
+use crate::error::{Result};
 
 pub struct Deserializer<T: BipackSource> {
     // This string starts with the input data and characters are truncated off
@@ -17,10 +17,10 @@ pub fn from_bytes<'de, T: Deserialize<'de>>(source: &[u8]) -> Result<T> {
 }
 
 impl<'de, 'a,  T: BipackSource> de::Deserializer<'de> for &'a mut Deserializer<T> {
-    type Error = Error;
+    type Error = BipackError;
 
     fn deserialize_any<V>(self, visitor: V) -> std::result::Result<V::Value, Self::Error> where V: Visitor<'de> {
-        Err(Error::NotPossible)
+        Err(BipackError::NotPossible)
     }
 
     fn deserialize_bool<V>(self, visitor: V) -> std::result::Result<V::Value, Self::Error> where V: Visitor<'de> {
@@ -60,17 +60,17 @@ impl<'de, 'a,  T: BipackSource> de::Deserializer<'de> for &'a mut Deserializer<T
     }
 
     fn deserialize_f32<V>(self, visitor: V) -> std::result::Result<V::Value, Self::Error> where V: Visitor<'de> {
-        Err(Error::NotImplemented)
+        Err(BipackError::NotImplemented)
     }
 
     fn deserialize_f64<V>(self, visitor: V) -> std::result::Result<V::Value, Self::Error> where V: Visitor<'de> {
-        Err(Error::NotImplemented)
+        Err(BipackError::NotImplemented)
     }
 
     fn deserialize_char<V>(self, visitor: V) -> std::result::Result<V::Value, Self::Error> where V: Visitor<'de> {
         let ch = self.input.get_str()?;
         if ch.len() != 1 {
-            Err(Error::BadFormat(format!("Char length is {}, should be 1 {:?}", ch.len(), ch)))
+            Err(BipackError::BadFormat(format!("Char length is {}, should be 1 {:?}", ch.len(), ch)))
         } else {
             visitor.visit_char(ch.chars().next().unwrap())
         }
@@ -149,11 +149,11 @@ impl<'de, 'a,  T: BipackSource> de::Deserializer<'de> for &'a mut Deserializer<T
     }
 
     fn deserialize_identifier<V>(self, visitor: V) -> std::result::Result<V::Value, Self::Error> where V: Visitor<'de> {
-        Err(Error::NotPossible)
+        Err(BipackError::NotPossible)
     }
 
     fn deserialize_ignored_any<V>(self, visitor: V) -> std::result::Result<V::Value, Self::Error> where V: Visitor<'de> {
-        Err(Error::NotPossible)
+        Err(BipackError::NotPossible)
     }
 
     fn is_human_readable(&self) -> bool {
@@ -162,13 +162,13 @@ impl<'de, 'a,  T: BipackSource> de::Deserializer<'de> for &'a mut Deserializer<T
 }
 
 impl<'de, 'a, T: BipackSource> serde::de::EnumAccess<'de> for &'a mut Deserializer<T> {
-    type Error = Error;
+    type Error = BipackError;
     type Variant = Self;
 
     #[inline]
     fn variant_seed<V: DeserializeSeed<'de>>(self, seed: V) -> Result<(V::Value, Self)> {
         let varint: u32 = self.input.get_unsigned()? as u32;
-        let v = DeserializeSeed::deserialize::<U32Deserializer<Error>>(
+        let v = DeserializeSeed::deserialize::<U32Deserializer<BipackError>>(
             seed,
             varint.into_deserializer())?;
         Ok((v, self))
@@ -176,7 +176,7 @@ impl<'de, 'a, T: BipackSource> serde::de::EnumAccess<'de> for &'a mut Deserializ
 }
 
 impl<'de, 'a, T: BipackSource> serde::de::VariantAccess<'de> for &'a mut Deserializer<T> {
-    type Error = Error;
+    type Error = BipackError;
 
     #[inline]
     fn unit_variant(self) -> Result<()> {
@@ -221,7 +221,7 @@ impl<'a, T: BipackSource> SimpleSeq<'a, T> {
 // `SeqAccess` is provided to the `Visitor` to give it the ability to iterate
 // through elements of the sequence.
 impl<'de, 'a, T: BipackSource> SeqAccess<'de> for SimpleSeq<'a, T> {
-    type Error = Error;
+    type Error = BipackError;
 
     fn next_element_seed<S>(&mut self, seed: S) -> Result<Option<S::Value>>
         where
@@ -242,7 +242,7 @@ struct SimpleMap<'a,  T: BipackSource> {
 }
 
 impl<'de, 'a, T: BipackSource> MapAccess<'de> for SimpleMap<'a,T> {
-    type Error = Error;
+    type Error = BipackError;
 
     fn next_key_seed<K>(&mut self, seed: K) -> std::result::Result<Option<K::Value>, Self::Error> where K: DeserializeSeed<'de> {
         if self.size < 1 {
@@ -264,10 +264,11 @@ mod tests {
     use std::fmt::Debug;
 
     use serde::{Deserialize, Serialize};
+    use crate::bipack_source::BipackError;
 
     use crate::de::from_bytes;
     use crate::error::Result;
-    use crate::ser::to_bytes;
+    use crate::ser::{to_buffer, to_bytes};
     use crate::tools::to_dump;
 
     #[test]
@@ -349,6 +350,17 @@ mod tests {
         let packed = to_bytes(x).unwrap();
         println!("packed {:?}:\n{}", x, to_dump(&packed) );
         assert_eq!(*x, from_bytes(&packed).unwrap());
+
+        let mut buffer = [0u8; 128];
+        let packed2 = to_buffer(x, & mut buffer).unwrap();
+        assert_eq!(*x, from_bytes(&packed2).unwrap());
+
+        if packed.len() > 1  {
+            let mut small_buffer = [0u8; 1];
+            let result = to_buffer(x, & mut small_buffer);
+            assert_eq!(true, result.is_err());
+            assert_eq!(BipackError::BufferOverflow, result.err().unwrap());
+        }
     }
 
     #[test]
diff --git a/src/error.rs b/src/error.rs
index ca8d4db..49e020b 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -1,51 +1,20 @@
 use std;
-use std::fmt::{self, Display};
+use std::fmt::Display;
+
 use serde::{de, ser};
+
 use crate::bipack_source::BipackError;
 
-pub type Result<T> = std::result::Result<T, Error>;
+pub type Result<T> = std::result::Result<T, BipackError>;
 
-#[derive(Debug)]
-pub enum Error {
-    Message(String),
-    BadFormat(String),
-    Eof,
-    ExtraBytes,
-    BadEncoding,
-    NotSupported,
-    NotImplemented,
-    NotPossible
-}
-
-impl Display for Error {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            Error::Message(msg) => formatter.write_str(msg),
-            _ => write!(formatter, "BiPack error: {:?}", self),
-        }
-    }
-}
-
-impl std::error::Error for Error {}
-
-impl ser::Error for Error {
+impl ser::Error for BipackError {
     fn custom<T: Display>(msg: T) -> Self {
-        Error::Message(msg.to_string())
+        BipackError::Message(msg.to_string())
     }
 }
 
-impl de::Error for Error {
+impl de::Error for BipackError {
     fn custom<T: Display>(msg: T) -> Self {
-        Error::Message(msg.to_string())
-    }
-}
-
-impl From<BipackError> for Error {
-    fn from(value: BipackError) -> Self {
-        match &value {
-            BipackError::NoDataError => Error::Eof,
-            BipackError::BadEncoding(_) => Error::BadEncoding,
-            // other => Error::Message(format!("BiPack error: {}", value))
-        }
+        BipackError::Message(msg.to_string())
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index 6457c38..72981f0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -124,6 +124,7 @@ pub mod de;
 pub mod crc;
 pub mod contrail;
 pub mod fixint;
+pub mod buffer_sink;
 
 #[cfg(test)]
 mod tests {
@@ -168,20 +169,20 @@ mod tests {
     #[test]
     fn fixed_pack() {
         let mut data: Vec<u8> = Vec::new();
-        data.put_u8(7);
-        data.put_u16(64000);
-        data.put_u32(66000);
-        data.put_u64(931127140399);
+        data.put_u8(7).unwrap();
+        data.put_u16(64000).unwrap();
+        data.put_u32(66000).unwrap();
+        data.put_u64(931127140399).unwrap();
         assert_eq!("07fa00000101d0000000d8cb80a02f", hex::encode(&data));
     }
 
     #[test]
     fn smart_pack() {
         let mut data: Vec<u8> = Vec::new();
-        data.put_u8(7);
-        data.put_unsigned(64000u16);
-        data.put_unsigned(66000u32);
-        data.put_unsigned(931127140399u64);
+        data.put_u8(7).unwrap();
+        data.put_unsigned(64000u16).unwrap();
+        data.put_unsigned(66000u32).unwrap();
+        data.put_unsigned(931127140399u64).unwrap();
         // println!("?? {}", hex::encode(&data));
         assert_eq!("0702e803420704bf8002aec60d", hex::encode(&data));
     }
@@ -189,7 +190,7 @@ mod tests {
     #[test]
     fn pack_varbinaries_and_string() {
         let mut data = Vec::<u8>::new();
-        data.put_str("Hello, rupack!");
+        data.put_str("Hello, rupack!").unwrap();
         println!("size ${}\n{}",data.len(), to_dump(&data));
         let mut src = SliceSource::from(&data);
         assert_eq!("Hello, rupack!", src.get_str().unwrap());
@@ -199,7 +200,7 @@ mod tests {
     fn test_signed() -> Result<()> {
         fn test64(value: i64) -> Result<()> {
             let mut x = Vec::new();
-            x.put_i64(value);
+            x.put_i64(value).unwrap();
             assert_eq!(value, SliceSource::from(&x).get_i64()?);
             Ok(())
         }
@@ -210,7 +211,7 @@ mod tests {
         test64(-9223372036854775808)?;
         fn test32(value: i32) -> Result<()> {
             let mut x = Vec::new();
-            x.put_i32(value);
+            x.put_i32(value).unwrap();
             assert_eq!(value, SliceSource::from(&x).get_i32()?);
             Ok(())
         }
@@ -221,7 +222,7 @@ mod tests {
         test32(-2147483648)?;
         fn test16(value: i16) -> Result<()> {
             let mut x = Vec::new();
-            x.put_i16(value);
+            x.put_i16(value).unwrap();
             assert_eq!(value, SliceSource::from(&x).get_i16()?);
             Ok(())
         }
@@ -254,7 +255,7 @@ mod tests {
     fn test_varsigned() -> Result<()> {
         fn test(value: i64) -> Result<()> {
             let mut x = Vec::new();
-            x.put_signed(value);
+            x.put_signed(value).unwrap();
             assert_eq!(value, SliceSource::from(&x).get_signed()?);
             Ok(())
         }
diff --git a/src/ser.rs b/src/ser.rs
index 82c58d9..b7d8483 100644
--- a/src/ser.rs
+++ b/src/ser.rs
@@ -1,7 +1,9 @@
 use serde::{ser, Serialize};
 
 use crate::bipack_sink::{BipackSink, IntoU64};
-use crate::error::{Error, Result};
+use crate::bipack_source::BipackError;
+use crate::buffer_sink::BufferSink;
+use crate::error::{Result};
 
 pub struct Serializer<S: BipackSink> {
     // This string starts empty and JSON is appended as values are serialized.
@@ -16,9 +18,15 @@ pub fn to_bytes<T>(value: &T) -> Result<Vec<u8>>
     Ok(serializer.output)
 }
 
+pub fn to_buffer<'a, T: Serialize>(value: &T, buffer: & 'a mut [u8]) -> Result<& 'a [u8]> {
+    let mut serializer = Serializer { output: BufferSink { buffer: buffer, pos: 0}};
+    value.serialize(&mut serializer)?;
+    Ok(serializer.output.result_slice())
+}
+
 impl<'a, S: BipackSink> ser::Serializer for &'a mut Serializer<S> {
     type Ok = ();
-    type Error = Error;
+    type Error = BipackError;
     type SerializeSeq = Self;
     type SerializeTuple = Self;
     type SerializeTupleStruct = Self;
@@ -28,17 +36,18 @@ impl<'a, S: BipackSink> ser::Serializer for &'a mut Serializer<S> {
     type SerializeStructVariant = Self;
 
     fn serialize_bool(self, v: bool) -> Result<()> {
-        self.output.put_u8(if v { 1 } else { 0 });
+        self.output.put_u8(if v { 1 } else { 0 })?;
         Ok(())
     }
 
     fn serialize_i8(self, v: i8) -> Result<()> {
-        self.output.put_i8(v);
+        self.output.put_i8(v)?;
         Ok(())
     }
 
     fn serialize_i16(self, v: i16) -> Result<()> {
-        self.serialize_i64(i64::from(v))
+        self.serialize_i64(i64::from(v))?;
+        Ok(())
     }
 
     fn serialize_i32(self, v: i32) -> Result<()> {
@@ -46,12 +55,12 @@ impl<'a, S: BipackSink> ser::Serializer for &'a mut Serializer<S> {
     }
 
     fn serialize_i64(self, v: i64) -> Result<()> {
-        self.output.put_signed(v);
+        self.output.put_signed(v)?;
         Ok(())
     }
 
     fn serialize_u8(self, v: u8) -> Result<()> {
-        self.output.put_u8(v);
+        self.output.put_u8(v)?;
         Ok(())
     }
     fn serialize_u16(self, v: u16) -> Result<()> {
@@ -63,7 +72,7 @@ impl<'a, S: BipackSink> ser::Serializer for &'a mut Serializer<S> {
         Ok(())
     }
     fn serialize_u64(self, v: u64) -> Result<()> {
-        self.output.put_unsigned(v);
+        self.output.put_unsigned(v)?;
         Ok(())
     }
 
@@ -82,12 +91,12 @@ impl<'a, S: BipackSink> ser::Serializer for &'a mut Serializer<S> {
     }
 
     fn serialize_str(self, v: &str) -> Result<()> {
-        self.output.put_str(v);
+        self.output.put_str(v)?;
         Ok(())
     }
 
     fn serialize_bytes(self, v: &[u8]) -> Result<()> {
-        self.output.put_var_bytes(v);
+        self.output.put_var_bytes(v)?;
         Ok(())
     }
 
@@ -149,7 +158,7 @@ impl<'a, S: BipackSink> ser::Serializer for &'a mut Serializer<S> {
 
     /// We expect it to use with vairable-length arrays...
     fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq> {
-        self.output.put_unsigned(_len.unwrap_or(0));
+        self.output.put_unsigned(_len.unwrap_or(0))?;
         Ok(self)
     }
 
@@ -178,7 +187,7 @@ impl<'a, S: BipackSink> ser::Serializer for &'a mut Serializer<S> {
     }
 
     fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
-        self.output.put_unsigned(_len.unwrap_or(0));
+        self.output.put_unsigned(_len.unwrap_or(0))?;
         Ok(self)
     }
 
@@ -197,7 +206,7 @@ impl<'a, S: BipackSink> ser::Serializer for &'a mut Serializer<S> {
         variant: &'static str,
         _len: usize,
     ) -> Result<Self::SerializeStructVariant> {
-        self.output.put_unsigned(_variant_index);
+        self.output.put_unsigned(_variant_index)?;
         Ok(self)
     }
 }
@@ -206,7 +215,7 @@ impl<'a, S: BipackSink> ser::SerializeSeq for &'a mut Serializer<S> {
     // Must match the `Ok` type of the serializer.
     type Ok = ();
     // Must match the `Error` type of the serializer.
-    type Error = Error;
+    type Error = BipackError;
 
     // Serialize a single element of the sequence.
     fn serialize_element<T>(&mut self, value: &T) -> Result<()>
@@ -224,7 +233,7 @@ impl<'a, S: BipackSink> ser::SerializeSeq for &'a mut Serializer<S> {
 
 impl<'a, S: BipackSink> ser::SerializeTuple for &'a mut Serializer<S> {
     type Ok = ();
-    type Error = Error;
+    type Error = BipackError;
 
     fn serialize_element<T>(&mut self, value: &T) -> Result<()>
         where
@@ -240,7 +249,7 @@ impl<'a, S: BipackSink> ser::SerializeTuple for &'a mut Serializer<S> {
 
 impl<'a, S: BipackSink> ser::SerializeTupleStruct for &'a mut Serializer<S> {
     type Ok = ();
-    type Error = Error;
+    type Error = BipackError;
 
     fn serialize_field<T>(&mut self, value: &T) -> Result<()>
         where
@@ -256,7 +265,7 @@ impl<'a, S: BipackSink> ser::SerializeTupleStruct for &'a mut Serializer<S> {
 
 impl<'a, S: BipackSink> ser::SerializeTupleVariant for &'a mut Serializer<S> {
     type Ok = ();
-    type Error = Error;
+    type Error = BipackError;
 
     fn serialize_field<T>(&mut self, value: &T) -> Result<()>
         where
@@ -272,7 +281,7 @@ impl<'a, S: BipackSink> ser::SerializeTupleVariant for &'a mut Serializer<S> {
 
 impl<'a, S: BipackSink> ser::SerializeMap for &'a mut Serializer<S> {
     type Ok = ();
-    type Error = Error;
+    type Error = BipackError;
 
     // The Serde data model allows map keys to be any serializable type. JSON
     // only allows string keys so the implementation below will produce invalid
@@ -308,7 +317,7 @@ impl<'a, S: BipackSink> ser::SerializeMap for &'a mut Serializer<S> {
 // constant strings.
 impl<'a, S: BipackSink> ser::SerializeStruct for &'a mut Serializer<S> {
     type Ok = ();
-    type Error = Error;
+    type Error = BipackError;
 
     fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
         where
@@ -324,7 +333,7 @@ impl<'a, S: BipackSink> ser::SerializeStruct for &'a mut Serializer<S> {
 
 impl<'a, S: BipackSink> ser::SerializeStructVariant for &'a mut Serializer<S> {
     type Ok = ();
-    type Error = Error;
+    type Error = BipackError;
 
     fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
         where