This commit introduces 128-bit integers. Stage 2 builds and produces a working compiler which
understands and supports 128-bit integers throughout.
The general strategy used is to have rustc_i128 module which provides aliases for iu128, equal to
iu64 in stage9 and iu128 later. Since nowhere in rustc we rely on large numbers being supported,
this strategy is good enough to get past the first bootstrap stages to end up with a fully working
128-bit capable compiler.
In order for this strategy to work, number of locations had to be changed to use associated
max_value/min_value instead of MAX/MIN constants as well as the min_value (or was it max_value?)
had to be changed to use xor instead of shift so both 64-bit and 128-bit based consteval works
(former not necessarily producing the right results in stage1).
This commit includes manual merge conflict resolution changes from a rebase by @est31.
Use Borrow for binary_search and contains methods in the standard library
Fixes all standard library methods in #32822 that can be fixed without backwards compatibility issues.
Forward more ExactSizeIterator methods and `is_empty` edits
- Forward ExactSizeIterator methods in more places, like `&mut I` and `Box<I>` iterator impls.
- Improve `VecDeque::is_empty` itself (see commit 4)
- All the collections iterators now have `len` or `is_empty` forwarded if doing so is a benefit. In the remaining cases, they already use a simple size hint (using something like a stored `usize` value), which is sufficient for the default implementation of len and is_empty.
Remove Self: Sized from Iterator::nth
It is an unnecessary restriction; nth neither needs self to be sized
nor needs to be exempted from the trait object.
It increases the utility of the nth method, because type specific
implementations are available through `&mut I` or through an iterator
trait object.
It is a backwards compatible change due to the special cases of the
`where Self: Sized` bound; it was already optional to include this bound
in `Iterator` implementations.
It is an unnecessary restriction; nth neither needs self to be sized
nor needs to be exempted from the trait object.
It increases the utility of the nth method, because type specific
implementations are available through `&mut I` or through an iterator
trait object.
It is a backwards compatible change due to the special cases of the
`where Self: Sized` bound; it was already optional to include this bound
in `Iterator` implementations.
Make core::fmt::Void a non-empty type.
Adding back this change that was removed from PR #36449 because it's a fix and because I immediately hit a problem with it again when I started implementing my fix for #12609.
Add rustbuild command `bench`
Add command bench to rustbuild, so that `./x.py bench <path>` can compile and run benchmarks.
`./x.py bench --stage 1 src/libcollections` and `./x.py bench --stage 1 src/libstd` should both compile well. Just `./x.py bench` runs all benchmarks for the libstd crates.
Fixes#37897
Fix two small issues in iterator docs
- `collect()` is a regular method, not an adaptor (does not return an Iterator). I just randomly picked `filter` as a third common adaptor to mention instead.
- Fix example in `Map`'s docs so that it uses the DoubleEndedIterator implementation
Forward ExactSizeIterator::len and is_empty for important iterator adaptors
Forward ExactSizeIterator::len and is_empty for important iterator adaptors
Because some iterators will provide improved version of len and/or is_empty,
adaptors should forward to those implementations if possible.
