Struct ReprOptions

pub struct ReprOptions {
    pub int: Option<IntegerType>,
    pub align: Option<Align>,
    pub pack: Option<Align>,
    pub flags: ReprFlags,
    pub field_shuffle_seed: u64,
}

Represents the repr options provided by the user.

Fields

int: Option<IntegerType>

align: Option<Align>

pack: Option<Align>

flags: ReprFlags

field_shuffle_seed: u64

The seed to be used for randomizing a type’s layout

Note: This could technically be a u128 which would be the “most accurate” hash as it’d encompass the item and crate hash without loss, but it does pay the price of being larger. Everything’s a tradeoff, a 64-bit seed should be sufficient for our purposes (primarily -Z randomize-layout)

Implementations

impl ReprOptions

pub fn simd(&self) -> bool

pub fn c(&self) -> bool

pub fn packed(&self) -> bool

pub fn transparent(&self) -> bool

pub fn linear(&self) -> bool

pub fn discr_type(&self) -> IntegerType

Returns the discriminant type, given these repr options. This must only be called on enums!

pub fn inhibit_enum_layout_opt(&self) -> bool

Returns true if this #[repr()] should inhabit “smart enum layout” optimizations, such as representing Foo<&T> as a single pointer.

pub fn inhibit_newtype_abi_optimization(&self) -> bool

pub fn inhibit_struct_field_reordering(&self) -> bool

Returns true if this #[repr()] guarantees a fixed field order, e.g. repr(C) or repr(<int>).

pub fn can_randomize_type_layout(&self) -> bool

Returns true if this type is valid for reordering and -Z randomize-layout was enabled for its declaration crate.

pub fn inhibits_union_abi_opt(&self) -> bool

Returns true if this #[repr()] should inhibit union ABI optimisations.

Trait Implementations

impl Clone for ReprOptions

fn clone(&self) -> ReprOptions

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ReprOptions

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<__D> Decodable<__D> for ReprOptions

where __D: Decoder,

fn decode(__decoder: &mut __D) -> ReprOptions

impl Default for ReprOptions

fn default() -> ReprOptions

Returns the “default value” for a type.

impl<__E> Encodable<__E> for ReprOptions

where __E: Encoder,

fn encode(&self, __encoder: &mut __E)

impl<__CTX> HashStable<__CTX> for ReprOptions

where __CTX: HashStableContext,

fn hash_stable( &self, __hcx: &mut __CTX, __hasher: &mut StableHasher<SipHasher128>, )

impl PartialEq for ReprOptions

fn eq(&self, other: &ReprOptions) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ReprOptions

impl Eq for ReprOptions

impl StructuralPartialEq for ReprOptions

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: 16 bytes