Implement more ExactSizeIterators on 64-bit platforms

[yhx-12243]

In 64-bit platforms Range<i64>, Range<u64>, RangeInclusive<i32> and RangeInclusive<u32> should implement ExactSizeIterator.

[rustbot]

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[rust-log-analyzer]

The job x86_64-gnu-tools failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

   Compiling getopts v0.2.21
error[E0034]: multiple applicable items in scope
    --> /cargo/registry/src/index.crates.io-6f17d22bba15001f/rustc-rayon-0.5.0/src/range.rs:256:44
     |
219  | / macro_rules! unindexed_range_impl {
220  | |     ( $t:ty, $len_t:ty ) => {
221  | |         impl UnindexedRangeLen<$len_t> for Range<$t> {
222  | |             fn len(&self) -> $len_t {
...    |
256  | |                 usize::try_from(iter.range.len()).ok()
     | |                                            ^^^ multiple `len` found
282  | |     };
283  | | }
     | |_- in this expansion of `unindexed_range_impl!`
...
...
296  |   unindexed_range_impl! {u64, u64}
     |
     |
note: candidate #1 is defined in an impl of the trait `UnindexedRangeLen` for the type `std::ops::Range<u64>`
     |
219  | / macro_rules! unindexed_range_impl {
219  | / macro_rules! unindexed_range_impl {
220  | |     ( $t:ty, $len_t:ty ) => {
221  | |         impl UnindexedRangeLen<$len_t> for Range<$t> {
222  | |             fn len(&self) -> $len_t {
...    |
282  | |     };
283  | | }
     | |_- in this expansion of `unindexed_range_impl!`
     | |_- in this expansion of `unindexed_range_impl!`
...
296  |   unindexed_range_impl! {u64, u64}
     = note: candidate #2 is defined in an impl of the trait `ExactSizeIterator` for the type `std::ops::Range<u64>`
     = note: candidate #2 is defined in an impl of the trait `ExactSizeIterator` for the type `std::ops::Range<u64>`
note: candidate #3 is defined in the trait `iter::IndexedParallelIterator`
     |
3111 |     fn len(&self) -> usize;
     |     ^^^^^^^^^^^^^^^^^^^^^^^
help: disambiguate the method for candidate #1
help: disambiguate the method for candidate #1
     |
256  |                 usize::try_from(UnindexedRangeLen::len(&iter.range)).ok()
help: disambiguate the method for candidate #2
     |
     |
256  |                 usize::try_from(ExactSizeIterator::len(&iter.range)).ok()
help: disambiguate the method for candidate #3
     |
     |
256  |                 usize::try_from(iter::IndexedParallelIterator::len(&iter.range)).ok()

error[E0034]: multiple applicable items in scope
    --> /cargo/registry/src/index.crates.io-6f17d22bba15001f/rustc-rayon-0.5.0/src/range.rs:264:40
     |
     |
219  | / macro_rules! unindexed_range_impl {
220  | |     ( $t:ty, $len_t:ty ) => {
221  | |         impl UnindexedRangeLen<$len_t> for Range<$t> {
222  | |             fn len(&self) -> $len_t {
...    |
264  | |                 let index = self.range.len() / 2;
     | |                                        ^^^ multiple `len` found
282  | |     };
283  | | }
     | |_- in this expansion of `unindexed_range_impl!`
...
...
296  |   unindexed_range_impl! {u64, u64}
     |
     |
note: candidate #1 is defined in an impl of the trait `UnindexedRangeLen` for the type `std::ops::Range<u64>`
     |
219  | / macro_rules! unindexed_range_impl {
219  | / macro_rules! unindexed_range_impl {
220  | |     ( $t:ty, $len_t:ty ) => {
221  | |         impl UnindexedRangeLen<$len_t> for Range<$t> {
222  | |             fn len(&self) -> $len_t {
...    |
282  | |     };
283  | | }
     | |_- in this expansion of `unindexed_range_impl!`
     | |_- in this expansion of `unindexed_range_impl!`
...
296  |   unindexed_range_impl! {u64, u64}
     = note: candidate #2 is defined in an impl of the trait `ExactSizeIterator` for the type `std::ops::Range<u64>`
     = note: candidate #2 is defined in an impl of the trait `ExactSizeIterator` for the type `std::ops::Range<u64>`
note: candidate #3 is defined in the trait `iter::IndexedParallelIterator`
     |
3111 |     fn len(&self) -> usize;
     |     ^^^^^^^^^^^^^^^^^^^^^^^
help: disambiguate the method for candidate #1
help: disambiguate the method for candidate #1
     |
264  |                 let index = UnindexedRangeLen::len(&self.range) / 2;
help: disambiguate the method for candidate #2
     |
     |
264  |                 let index = ExactSizeIterator::len(&self.range) / 2;
help: disambiguate the method for candidate #3
     |
     |
264  |                 let index = iter::IndexedParallelIterator::len(&self.range) / 2;

error[E0034]: multiple applicable items in scope
    --> /cargo/registry/src/index.crates.io-6f17d22bba15001f/rustc-rayon-0.5.0/src/range.rs:256:44
     |
     |
219  | / macro_rules! unindexed_range_impl {
220  | |     ( $t:ty, $len_t:ty ) => {
221  | |         impl UnindexedRangeLen<$len_t> for Range<$t> {
222  | |             fn len(&self) -> $len_t {
...    |
256  | |                 usize::try_from(iter.range.len()).ok()
     | |                                            ^^^ multiple `len` found
282  | |     };
283  | | }
     | |_- in this expansion of `unindexed_range_impl!`
...
...
297  |   unindexed_range_impl! {i64, u64}
     |
     |
note: candidate #1 is defined in an impl of the trait `UnindexedRangeLen` for the type `std::ops::Range<i64>`
     |
219  | / macro_rules! unindexed_range_impl {
219  | / macro_rules! unindexed_range_impl {
220  | |     ( $t:ty, $len_t:ty ) => {
221  | |         impl UnindexedRangeLen<$len_t> for Range<$t> {
222  | |             fn len(&self) -> $len_t {
...    |
282  | |     };
283  | | }
     | |_- in this expansion of `unindexed_range_impl!`
     | |_- in this expansion of `unindexed_range_impl!`
...
297  |   unindexed_range_impl! {i64, u64}
     |   -------------------------------- in this macro invocation
     = note: candidate #2 is defined in an impl of the trait `ExactSizeIterator` for the type `std::ops::Range<i64>`
note: candidate #3 is defined in the trait `iter::IndexedParallelIterator`
     |
3111 |     fn len(&self) -> usize;
     |     ^^^^^^^^^^^^^^^^^^^^^^^
help: disambiguate the method for candidate #1
help: disambiguate the method for candidate #1
     |
256  |                 usize::try_from(UnindexedRangeLen::len(&iter.range)).ok()
help: disambiguate the method for candidate #2
     |
     |
256  |                 usize::try_from(ExactSizeIterator::len(&iter.range)).ok()
help: disambiguate the method for candidate #3
     |
     |
256  |                 usize::try_from(iter::IndexedParallelIterator::len(&iter.range)).ok()

   Compiling memoffset v0.9.1
   Compiling rustc_apfloat v0.2.0+llvm-462a31f5a5ab
error[E0034]: multiple applicable items in scope
error[E0034]: multiple applicable items in scope
    --> /cargo/registry/src/index.crates.io-6f17d22bba15001f/rustc-rayon-0.5.0/src/range.rs:264:40
     |
219  | / macro_rules! unindexed_range_impl {
220  | |     ( $t:ty, $len_t:ty ) => {
221  | |         impl UnindexedRangeLen<$len_t> for Range<$t> {
222  | |             fn len(&self) -> $len_t {
...    |
264  | |                 let index = self.range.len() / 2;
     | |                                        ^^^ multiple `len` found
282  | |     };
283  | | }
     | |_- in this expansion of `unindexed_range_impl!`
...
...
297  |   unindexed_range_impl! {i64, u64}
     |
     |
note: candidate #1 is defined in an impl of the trait `UnindexedRangeLen` for the type `std::ops::Range<i64>`
     |
219  | / macro_rules! unindexed_range_impl {
219  | / macro_rules! unindexed_range_impl {
220  | |     ( $t:ty, $len_t:ty ) => {
221  | |         impl UnindexedRangeLen<$len_t> for Range<$t> {
222  | |             fn len(&self) -> $len_t {
...    |
282  | |     };
283  | | }
     | |_- in this expansion of `unindexed_range_impl!`
     | |_- in this expansion of `unindexed_range_impl!`
...
297  |   unindexed_range_impl! {i64, u64}
     |   -------------------------------- in this macro invocation
     = note: candidate #2 is defined in an impl of the trait `ExactSizeIterator` for the type `std::ops::Range<i64>`
note: candidate #3 is defined in the trait `iter::IndexedParallelIterator`
     |
3111 |     fn len(&self) -> usize;
     |     ^^^^^^^^^^^^^^^^^^^^^^^
help: disambiguate the method for candidate #1
help: disambiguate the method for candidate #1
     |
264  |                 let index = UnindexedRangeLen::len(&self.range) / 2;
help: disambiguate the method for candidate #2
     |
     |
264  |                 let index = ExactSizeIterator::len(&self.range) / 2;
help: disambiguate the method for candidate #3
     |
     |
264  |                 let index = iter::IndexedParallelIterator::len(&self.range) / 2;

   Compiling rustc_version v0.4.0
   Compiling datafrog v2.0.1
   Compiling bitflags v1.3.2

[yhx-12243]

This will partially affect
https://github.com/rust-lang/rustc-rayon/blob/f192a484741522bccb411cb5f1da9ec9577d6e27/src/range.rs#L296-L299
I think it should become a issue (feature request) now.

[Noratrieb]

we generally want to avoid such portability surprises like this would introduce

[scottmcm]

Adding these would be a pretty substantial policy change, so it's not something I can just decide in a PR.

Please open an API Change Proposal for libs-api to consider if you wish to do this, but for now I'm going to close the PR.

I suspect it's more likely that the way forward here (if anything) is something like what's described in #41619 (comment) , and not something based on conditional compilation cfgs.