# Function untrusted::read_all_optional [−] [src]

    pub fn read_all_optional<'a, F, R, E>(
        input: Option<Input<'a>>,
        incomplete_read: E,
        read: F
    ) -> Result<R, E> where
        F: FnOnce(Option<&mut Reader>) -> Result<R, E>,

Calls `read` with the given input as a `Reader`, ensuring that `read` consumed the entire input. When `input` is `None`, `read` will be called with `None`.

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