"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.
- Make `extern fn()` assignable to any closure type, rather than
a subtype.
- Remove unused int_ty_set and float_ty_set
- Refactor variable unification and make it more DRY
- Do fn sub/lub/glb on the level of fn_sig
- Rename infer::to_str::ToStr to infer::to_str::InferStr
- Capitalize names of various types
- Correct hashing of FnMeta
- Convert various records-of-fns into structs-of-fns. This is both
eliminating use of deprecated features and more forwards compatible
with fn reform.
r=pcwalton
and rename "class" to "struct" everywhere possible (except local
vars, I was too lazy for that) -- that is why this commit is so
big.
No review, just dead code removal and renaming.
Closes#3515
This allows more errors to be non-fatal, as per #1871.
I only went through and started changing span_fatal to span_err in
check.rs. There are probably more errors that could be made
non-fatal. So if you see derived type errors appearing from now on,
file a bug!
r=graydon
Closes#1871
