This contains a pure Odin implementation of the msgpack spec, including timestamps. There is currently no support for any extensions. If this is a need you have, I'd suggest using a binary field and packing your data there. Having ext types makes the unpacker/packer more complex, for no good reason.

A few notes on compatibility:

• Integers are packed into the smallest possible variant
• Floats are packed as is and deserialized as is TODO: Unit tests assume efficient packing so right now, anything < F32_MAX is packed as f32. This is temporary.
• []u8 and friends are packed as Array[Number]. This is also true for []byte, which is a soft alias for the former. For true binary data, use []m.bin or m.binary.
• Packing internally uses a bufio.Writer. pack_into_from_ will flush this, but manual packing requires flushing this explicitly. See packer_flush.
• Unions are packed as {variant_name_or_index: variant_value}
• .StableMaps do not apply to structs, only actual maps.

• There's no support for enums (yet)
• No support for using in structs

I haven't measured against every encoding shipped by default with Odin, only CBOR. The reason for this is that CBOR is pretty much msgpack, so that's our baseline to beat. As can be seen in the baseline below, we're slightly faster on unpack, but almost four times as fast when packing. A major difference here could be using bufio.Writer, as the serialization stack is fairly similar otherwise.