pub enum UnstableFeatures {
    Disallow,
    Allow,
    Cheat,
}

Variants

Disallow

Hard errors for unstable features are active, as on beta/stable channels.

Allow

Allow features to be activated, as on nightly.

Cheat

Errors are bypassed for bootstrapping. This is required any time during the build that feature-related lints are set to warn or above because the build turns on warnings-as-errors and uses lots of unstable features. As a result, this is always required for building Rust itself.

Implementations

This takes into account RUSTC_BOOTSTRAP.

If krate is Some, then setting RUSTC_BOOTSTRAP=krate will enable the nightly features. Otherwise, only RUSTC_BOOTSTRAP=1 will work.

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Feeds this value into the given Hasher. Read more

Feeds a slice of this type into the given Hasher. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

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

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.

Size: 1 byte

Size for each variant:

  • Disallow: 0 bytes
  • Allow: 0 bytes
  • Cheat: 0 bytes