To me the biggest reason for the surprise is the signature for 'write' I'm used to a raw stream allowing a few specific operations: - read/write/peek one byte

To me the biggest reason for the surprise is the signature for 'write' I'm used to a raw stream allowing a few specific operations: - read/write/peek one byte - write a byte array, but you must explicitly specify length and offset So seeing a call that simply takes an entire byte string and writes it gives me "buffered I/O vibes". It's hard to quantify, but with how ubiquitous that pattern is I'd be surprised if there are a lot of people who expect similar.