I've added trt_field_vtable, trt_field_box, and trt_field_tydesc, and
inserted them in place of the "magic numbers" used to access trait
object fields through GEPi().
- In a TraitRef, use the self type consistently to refer to the Self type:
- trait ref in `impl Trait<A,B,C> for S` has a self type of `S`.
- trait ref in `A:Trait` has the self type `A`
- trait ref associated with a trait decl has self type `Self`
- trait ref associated with a supertype has self type `Self`
- trait ref in an object type `@Trait` has no self type
- Rewrite `each_bound_traits_and_supertraits` to perform
substitutions as it goes, and thus yield a series of trait refs
that are always in the same 'namespace' as the type parameter
bound given as input. Before, we left this to the caller, but
this doesn't work because the caller lacks adequare information
to perform the type substitutions correctly.
- For provided methods, substitute the generics involved in the provided
method correctly.
- Introduce TypeParameterDef, which tracks the bounds declared on a type
parameter and brings them together with the def_id and (in the future)
other information (maybe even the parameter's name!).
- Introduce Subst trait, which helps to cleanup a lot of the
repetitive code involved with doing type substitution.
- Introduce Repr trait, which makes debug printouts far more convenient.
Fixes#4183. Needed for #5656.
bare function store (which is not in fact a kind of value) but rather
ty::TraitRef. Removes many uses of fail!() and other telltale signs of
type-semantic mismatch.
cc #4183 (not a fix, but related)
and from typeck, which is verboten. We are supposed to write inference results
into the FnCtxt and then these get copied over in writeback. Add assertions
that no inference by-products are added to this table.
Fixes#3888Fixes#4036Fixes#4492
Major changes are:
- replace ~[ty_param] with Generics structure, which includes
both OptVec<TyParam> and OptVec<Lifetime>;
- the use of syntax::opt_vec to avoid allocation for empty lists;
cc #4846
LinearMap is quite a bit faster, and is fully owned/sendable without
requiring copies. The older std::map also doesn't use explicit self and
relies on mutable fields.
Add a new method_super origin for supertrait methods. Also make
coherence create a table that maps pairs of trait IDs and self types
to impl IDs, so that it's possible to check a supertrait method
knowing only its index in its trait's methods (without knowing all
supertraits for a given trait).
r=nmatsakis and graydon -- with hope, we'll revamp all of this code as
per #4678, but for now this fixes the bug.
Closes#3979
"Dual impls" are impls that are both type implementations and trait
implementations. They can lead to ambiguity and so this patch removes them
from the language.
This also enforces coherence rules. Without this patch, records can implement
traits not defined in the current crate. This patch fixes this, and updates
all of rustc to adhere to the new enforcement. Most of this patch is fixing
rustc to obey the coherence rules, which involves converting a bunch of records
to structs.