pub enum DefiningTy<'tcx> {
    Generator(DefIdSubstsRef<'tcx>, Movability),
Expand description

The “defining type” for this MIR. The key feature of the “defining type” is that it contains the information needed to derive all the universal regions that are in scope as well as the types of the inputs/output from the MIR. In general, early-bound universal regions appear free in the defining type and late-bound regions appear bound in the signature.



The MIR is a closure. The signature is found via ClosureSubsts::closure_sig_ty.

Generator(DefIdSubstsRef<'tcx>, Movability)

The MIR is a generator. The signature is that generators take no parameters and return the result of ClosureSubsts::generator_return_ty.


The MIR is a fn item with the given DefId and substs. The signature of the function can be bound then with the fn_sig query.


The MIR represents some form of constant. The signature then is that it has no inputs and a single return value, which is the value of the constant.


The MIR represents an inline const. The signature has no inputs and a single return value found via InlineConstSubsts::ty.


Returns a list of all the upvar types for this MIR. If this is not a closure or generator, there are no upvars, and hence it will be an empty list. The order of types in this list will match up with the upvar order in the HIR, typesystem, and MIR.

Number of implicit inputs – notably the “environment” parameter for closures – that appear in MIR but not in the user’s code.

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

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.


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: 24 bytes

Size for each variant:

  • Closure: 23 bytes
  • Generator: 23 bytes
  • FnDef: 23 bytes
  • Const: 23 bytes
  • InlineConst: 23 bytes