assertion failed: len < INLINE_CAP

[nnovikov]

I try to use serde for serialization data from my structs to BytesMut (it's default buffer type for tokio encoder). For serialization [u8; 16] serde call serialize_u8 method:

fn serialize_u8(self, v: u8) -> Result<(), error::Error> {
    self.writer.put_u8(v);
    Ok(())
}

and paniced with

thread 'tokio-runtime-worker-2' panicked at 'assertion failed: len < INLINE_CAP', /home/nnovikov/.cargo/registry/src/github.com-1ecc6299db9ec823/bytes-0.4.12/src/bytes.rs:1875:13

BytesMut crated with capacity 1024 bytes. Serialized structure have size about 50-60 bytes.
Is it possible bug in bytes? Or I am doing something wrong?

Dependence from Cargo.toml:

bytes = { version = "0.4.12", features = ["serde"] }

[seanmonstar]

Yes, that assert is internal and thus a bug. How are you creating the BytesMut? For some reason, the put_u8 method thinks self.is_inline() is true...

[tanriol]

Actually looks like this may be intentional: put_u8 is explicitly documented to panic if there is not enough remaining capacity and that's what it does (in bytes 0.4 series which did not implicitly increase capacity).