pub enum MonoItem<'tcx> {
    Fn(Instance<'tcx>),
    Static(DefId),
    GlobalAsm(ItemId),
}

Variants

Fn(Instance<'tcx>)

Static(DefId)

GlobalAsm(ItemId)

Implementations

Returns true if the mono item is user-defined (i.e. not compiler-generated, like shims).

Returns true if this instance is instantiable - whether it has no unsatisfied predicates.

In order to codegen an item, all of its predicates must hold, because otherwise the item does not make sense. Type-checking ensures that the predicates of every item that is used by a valid item do hold, so we can rely on that.

However, we codegen collector roots (reachable items) and functions in vtables when they are seen, even if they are not used, and so they might not be instantiable. For example, a programmer can define this public function:

pub fn foo<'a>(s: &'a mut ()) where &'a mut (): Clone {
    <&mut () as Clone>::clone(&s);
}

That function can’t be codegened, because the method <&mut () as Clone>::clone does not exist. Luckily for us, that function can’t ever be used, because that would require for &'a mut (): Clone to hold, so we can just not emit any code, or even a linker reference for it.

Similarly, if a vtable method has such a signature, and therefore can’t be used, we can just not emit it and have a placeholder (a null pointer, which will never be accessed) in its place.

Returns the item’s CrateNum

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

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

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

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

This method turns the parameters of a DepNodeConstructor into an opaque Fingerprint to be used in DepNode. Not all DepNodeParams support being turned into a Fingerprint (they don’t need to if the corresponding DepNode is anonymous). Read more

This method tries to recover the query key from the given DepNode, something which is needed when forcing DepNodes during red-green evaluation. The query system will only call this method if fingerprint_style() is not FingerprintStyle::Opaque. It is always valid to return None here, in which case incremental compilation will treat the query as having changed instead of forcing it. 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

Converts the given value to a String. 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: 40 bytes

Size for each variant:

  • Fn: 36 bytes
  • Static: 8 bytes
  • GlobalAsm: 4 bytes