Struct MatchArgChoicesEntry

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pub struct MatchArgChoicesEntry {
    pub placeholder: &'static str,
    pub choices_str: fn() -> String,
    pub preferred_default: &'static str,
}

Expand description

Entry for replacing match_arg placeholder defaults with actual choices.

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§placeholder: &'static str

Placeholder string in the R formal default, e.g. ".__MX_MATCH_ARG_CHOICES_mode__".

§choices_str: fn() -> String

Function that returns the choices as a comma-separated quoted string, e.g. "\"Fast\", \"Safe\", \"Debug\"".

§preferred_default: &'static str

User-supplied default = "..." value (unquoted, e.g. "zstd"), or "" if the user did not supply one. When non-empty, the write-time pass rotates the choice list so this value appears first, so R’s match.arg(arg) (no second arg) picks it as the default.

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impl Sync for MatchArgChoicesEntry

Auto Trait Implementations§

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impl UnwindSafe for MatchArgChoicesEntry

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> SizeHint for T
where T: ?Sized,

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default fn lower_bound(&self) -> usize

🔬This is a nightly-only experimental API. (core_io_internals)

Returns a lower bound on the number of elements this container-like item contains. For example, an array [u8; 12] could return any value between 0 and 12 inclusively as a correct implementation. Read more

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default fn upper_bound(&self) -> Option<usize>

🔬This is a nightly-only experimental API. (core_io_internals)

Returns an upper bound on the number of elements this container-like item contains if it can be determined, otherwise None. Read more

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final fn size_hint(&self) -> (usize, Option<usize>)

🔬This is a nightly-only experimental API. (core_io_internals)

Returns an estimate for the number of elements this container like type contains. Read more

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