Struct DeducedParamAttrs 

pub struct DeducedParamAttrs {
    pub usage: UsageSummary,
}

Parameter attributes that can only be determined by examining the body of a function instead of just its signature.

These can be useful for optimization purposes when a function is directly called. We compute them and store them into the crate metadata so that downstream crates can make use of them.

Right now, we have readonly and captures(none), but no_alias might be useful in the future.

Fields

usage: UsageSummary

Implementations

impl DeducedParamAttrs

pub fn is_default(self) -> bool

Returns true if no attributes have been deduced.

pub fn read_only<'tcx>( &self, tcx: TyCtxt<'tcx>, typing_env: TypingEnv<'tcx>, ty: Ty<'tcx>, ) -> bool

For parameters passed indirectly, returns true if pointer is never written through.

pub fn captures_none<'tcx>( &self, tcx: TyCtxt<'tcx>, typing_env: TypingEnv<'tcx>, ty: Ty<'tcx>, ) -> bool

For parameters passed indirectly, returns true if pointer is not captured, i.e., its address is not captured, and pointer is used neither for reads nor writes after function returns.

Trait Implementations

impl Clone for DeducedParamAttrs

fn clone(&self) -> DeducedParamAttrs

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DeducedParamAttrs

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

Formats the value using the given formatter.

impl<__D: SpanDecoder> Decodable<__D> for DeducedParamAttrs

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

impl<__E: SpanEncoder> Encodable<__E> for DeducedParamAttrs

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

impl Erasable for DeducedParamAttrs

type Storage = [u8; 1]

Storage type to used for erased values of this type. Should be [u8; N], where N is equal to size_of::<Self>.

impl<'__ctx> HashStable<StableHashingContext<'__ctx>> for DeducedParamAttrs

fn hash_stable( &self, __hcx: &mut StableHashingContext<'__ctx>, __hasher: &mut StableHasher, )

impl PartialEq for DeducedParamAttrs

fn eq(&self, other: &DeducedParamAttrs) -> 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<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for DeducedParamAttrs

fn decode(decoder: &mut D) -> &'tcx Self

impl Copy for DeducedParamAttrs

impl StructuralPartialEq for DeducedParamAttrs

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