- Correctly categorize env pointer deref for `FnMut` as declared
rather than inherited. This fixes an assert in borrowck.
Closes#18238
- Categorize env pointer deref as mutable only if the closure is
`FnMut` *and* the original variable is declared mutable. This
disallows capture-by-value `FnMut` closures from mutating captured
variables that aren't declared mutable. This is a difference
from the equivalent desugared code which would permit it, but
it is consistent with the behavior of procs. Closes#18335
- Avoid computing info about the env pointer if there isn't one.
This should be clearer, and fits in better with the `TTNonterminal` variant.
Renames:
- `TTTok` -> `TTToken`
- `TTDelim` -> `TTDelimited`
- `TTSeq` -> `TTSequence`
This came up when working [on the gl-rs generator extension](990383de80/src/gl_generator/lib.rs (L135-L146)).
The new definition of `TTDelim` adds an associated `Span` that covers the whole token tree and enforces the invariant that a delimited sequence of token trees must have an opening and closing delimiter.
A `get_span` method has also been added to `TokenTree` type to make it easier to implement better error messages for syntax extensions.
The real size is also more useful than just a boolean, and the caller
can easily determine if the operation failed from the real size. In most
cases, the caller is only going to be growing the allocation so a branch
can be avoided.
[breaking-change]
The C standard library functions should be used directly. The quirky
NULL / zero-size allocation workaround is no longer necessary and was
adding an extra branch to the allocator code path in a build without
jemalloc. This is a small step towards liballoc being compatible with
handling OOM errors instead of aborting (#18292).
[breaking-change]
With MIN_ALIGN as a static, other crates don't have access to its value
at compile time, because it is an extern global. That means that the
checks against it can't be optimized out, which is rather unfortunate.
So let's make it a constant instead.
Explain the primary disadvantage of garbage collection is runtime
overhead and unpredictable pauses. Elucidate where the name "race
condition" comes from. Emphasize that Rust can guarantee your code is
free of race conditions and other memory errors, with no runtime
overhead.
cc @steveklabnik
Rather than doing it top-down, with a known expected type, we will now simply establish the appropriate constraints between the pattern and the expression it destructures.
Closes#8783.
Closes#10200.
Adds an `assume` intrinsic that gets translated to llvm.assume. It is
used on a boolean expression and allows the optimizer to assume that
the expression is true.
This implements #18051.
Instead of checking patterns in a top-down fashion with a known
expected type on entry, this changes makes typeck establish
appropriate constraints between a pattern and the expression
it destructures, and lets inference compute the final types
or produce good error messages if it's impossible.
