Adds an assert_eq! macro that asserts that its two arguments are equal. Error messages can therefore be somewhat more informative than a simple assert, because the error message includes "expected" and "given" values.
Removes a lot of instances of `/*bad*/ copy` throughout libsyntax/librustc. On the plus side, this shaves about 2s off of the runtime when compiling `librustc` with optimizations.
Ideally I would have run a profiler to figure out which copies are the most critical to remove, but in reality there was a liberal amount of `git grep`s along with some spot checking and removing the easy ones.
For bootstrapping purposes, this commit does not remove all uses of
the keyword "pure" -- doing so would cause the compiler to no longer
bootstrap due to some syntax extensions ("deriving" in particular).
Instead, it makes the compiler ignore "pure". Post-snapshot, we can
remove "pure" from the language.
There are quite a few (~100) borrow check errors that were essentially
all the result of mutable fields or partial borrows of `@mut`. Per
discussions with Niko I think we want to allow partial borrows of
`@mut` but detect obvious footguns. We should also improve the error
message when `@mut` is erroneously reborrowed.
r? @graydon
This removes `log` from the language. Because we can't quite implement it as a syntax extension (probably need globals at the least) it simply renames the keyword to `__log` and hides it behind macros.
After this the only way to log is with `debug!`, `info!`, etc. I figure that if there is demand for `log!` we can add it back later.
I am not sure that we ever agreed on this course of action, though I *think* there is consensus that `log` shouldn't be a statement.
These changes make const translation use adjustments (autodereference, autoreference, bare-fn-to-closure), like normal code does, replacing some ad-hoc logic that wasn't always right.
As a convenient side-effect, explicit dereference (both of pointers and of newtypes) is also supported in const expressions.
There is also a “bonus fix” for a bug in the pretty-printer exposed by one of the added tests.
