File-sink-append-mode

Read the current append-mode policy used by a FileSink. This helper exposes whether future reopen behavior is currently append-oriented for the concrete sink value.

Interface

pub fn FileSink::append_mode(self : FileSink) -> Bool {

input

• self : FileSink - File sink whose current append-mode policy should be inspected.

output

• Bool - Current append-mode policy for the sink.

Explanation

Detailed rules explaining key parameters and behaviors

• This method reads the sink's current runtime append policy.
• The value affects later reopen(...) behavior.
• It does not report whether a file is currently writable or available.
• This helper does not mutate sink state.

How to Use

Here are some specific examples provided.

When Need Direct Append-policy Visibility

When diagnostics should show how future reopen behavior is configured:

let append = sink.append_mode()

In this example, the concrete file sink exposes its current append policy directly.

When Validate Policy Updates

When a setter call should be observed immediately:

sink.set_append_mode(true)
ignore(sink.append_mode())

In this example, callers verify the updated append-mode policy on the sink itself.

Error Case

e.g.:

• If callers need the full current file policy rather than just append mode, policy() is the better API.

• This helper alone does not prove the sink is currently open; use is_available() for that.

Notes

1. Use this helper when append policy is the only file setting you need to inspect.

2. Pair it with reopen helpers when debugging direct file-sink behavior.