Replace usages of ..i + 1 ranges with ..=i.

src/liballoc/collections/vec_deque.rs

@@ -2795,7 +2795,7 @@ mod tests {
             // 0, 1, 2, .., len - 1
             let expected = (0..).take(len).collect::<VecDeque<_>>();
             for tail_pos in 0..cap {
-                for to_remove in 0..len + 1 {
+                for to_remove in 0..=len {
                     tester.tail = tail_pos;
                     tester.head = tail_pos;
                     for i in 0..len {
@@ -2821,10 +2821,10 @@ mod tests {
         let mut tester: VecDeque<usize> = VecDeque::with_capacity(7);
 
         let cap = tester.capacity();
-        for len in 0..cap + 1 {
-            for tail in 0..cap + 1 {
-                for drain_start in 0..len + 1 {
-                    for drain_end in drain_start..len + 1 {
+        for len in 0..=cap {
+            for tail in 0..=cap {
+                for drain_start in 0..=len {
+                    for drain_end in drain_start..=len {
                         tester.tail = tail;
                         tester.head = tail;
                         for i in 0..len {
@@ -2866,10 +2866,10 @@ mod tests {
         tester.reserve(63);
         let max_cap = tester.capacity();
 
-        for len in 0..cap + 1 {
+        for len in 0..=cap {
             // 0, 1, 2, .., len - 1
             let expected = (0..).take(len).collect::<VecDeque<_>>();
-            for tail_pos in 0..max_cap + 1 {
+            for tail_pos in 0..=max_cap {
                 tester.tail = tail_pos;
                 tester.head = tail_pos;
                 tester.reserve(63);
@@ -2899,7 +2899,7 @@ mod tests {
         // len is the length *before* splitting
         for len in 0..cap {
             // index to split at
-            for at in 0..len + 1 {
+            for at in 0..=len {
                 // 0, 1, 2, .., at - 1 (may be empty)
                 let expected_self = (0..).take(at).collect::<VecDeque<_>>();
                 // at, at + 1, .., len - 1 (may be empty)
@@ -2927,7 +2927,7 @@ mod tests {
     fn test_from_vec() {
         use vec::Vec;
         for cap in 0..35 {
-            for len in 0..cap + 1 {
+            for len in 0..=cap {
                 let mut vec = Vec::with_capacity(cap);
                 vec.extend(0..len);
 

src/liballoc/tests/binary_heap.rs

@@ -318,11 +318,11 @@ fn panic_safe() {
     const NTEST: usize = 10;
 
     // don't use 0 in the data -- we want to catch the zeroed-out case.
-    let data = (1..DATASZ + 1).collect::<Vec<_>>();
+    let data = (1..=DATASZ).collect::<Vec<_>>();
 
     // since it's a fuzzy test, run several tries.
     for _ in 0..NTEST {
-        for i in 1..DATASZ + 1 {
+        for i in 1..=DATASZ {
             DROP_COUNTER.store(0, Ordering::SeqCst);
 
             let mut panic_ords: Vec<_> = data.iter()

src/liballoc/tests/btree/map.rs

@@ -302,7 +302,7 @@ fn test_range() {
     for i in 0..size {
         for j in i..size {
             let mut kvs = map.range((Included(&i), Included(&j))).map(|(&k, &v)| (k, v));
-            let mut pairs = (i..j + 1).map(|i| (i, i));
+            let mut pairs = (i..=j).map(|i| (i, i));
 
             for (kv, pair) in kvs.by_ref().zip(pairs.by_ref()) {
                 assert_eq!(kv, pair);
@@ -321,7 +321,7 @@ fn test_range_mut() {
     for i in 0..size {
         for j in i..size {
             let mut kvs = map.range_mut((Included(&i), Included(&j))).map(|(&k, &mut v)| (k, v));
-            let mut pairs = (i..j + 1).map(|i| (i, i));
+            let mut pairs = (i..=j).map(|i| (i, i));
 
             for (kv, pair) in kvs.by_ref().zip(pairs.by_ref()) {
                 assert_eq!(kv, pair);

src/liballoc/tests/str.rs

@@ -1378,7 +1378,7 @@ fn test_bool_from_str() {
 fn check_contains_all_substrings(s: &str) {
     assert!(s.contains(""));
     for i in 0..s.len() {
-        for j in i+1..s.len() + 1 {
+        for j in i+1..=s.len() {
             assert!(s.contains(&s[i..j]));
         }
     }

src/liballoc/tests/vec_deque.rs

@@ -861,15 +861,15 @@ fn test_as_slices() {
         ring.push_back(i);
 
         let (left, right) = ring.as_slices();
-        let expected: Vec<_> = (0..i + 1).collect();
+        let expected: Vec<_> = (0..=i).collect();
         assert_eq!(left, &expected[..]);
         assert_eq!(right, []);
     }
 
     for j in -last..0 {
         ring.push_front(j);
         let (left, right) = ring.as_slices();
-        let expected_left: Vec<_> = (-last..j + 1).rev().collect();
+        let expected_left: Vec<_> = (-last..=j).rev().collect();
         let expected_right: Vec<_> = (0..first).collect();
         assert_eq!(left, &expected_left[..]);
         assert_eq!(right, &expected_right[..]);
@@ -889,15 +889,15 @@ fn test_as_mut_slices() {
         ring.push_back(i);
 
         let (left, right) = ring.as_mut_slices();
-        let expected: Vec<_> = (0..i + 1).collect();
+        let expected: Vec<_> = (0..=i).collect();
         assert_eq!(left, &expected[..]);
         assert_eq!(right, []);
     }
 
     for j in -last..0 {
         ring.push_front(j);
         let (left, right) = ring.as_mut_slices();
-        let expected_left: Vec<_> = (-last..j + 1).rev().collect();
+        let expected_left: Vec<_> = (-last..=j).rev().collect();
         let expected_right: Vec<_> = (0..first).collect();
         assert_eq!(left, &expected_left[..]);
         assert_eq!(right, &expected_right[..]);

src/librustc/hir/map/hir_id_validator.rs

@@ -100,7 +100,7 @@ impl<'a, 'hir: 'a> HirIdValidator<'a, 'hir> {
 
         if max != self.hir_ids_seen.len() - 1 {
             // Collect the missing ItemLocalIds
-            let missing: Vec<_> = (0 .. max as u32 + 1)
+            let missing: Vec<_> = (0 ..= max as u32)
               .filter(|&i| !self.hir_ids_seen.contains_key(&ItemLocalId::from_u32(i)))
               .collect();
 

src/librustc/mir/mod.rs

@@ -339,7 +339,7 @@ impl<'tcx> Mir<'tcx> {
     #[inline]
     pub fn args_iter(&self) -> impl Iterator<Item = Local> {
         let arg_count = self.arg_count;
-        (1..arg_count + 1).map(Local::new)
+        (1..=arg_count).map(Local::new)
     }
 
     /// Returns an iterator over all user-defined variables and compiler-generated temporaries (all

src/librustc_apfloat/ieee.rs

@@ -571,7 +571,7 @@ impl<S: Semantics> fmt::Display for IeeeFloat<S> {
             }
             // Fill with zeros up to precision.
             if !truncate_zero && precision > digits - 1 {
-                for _ in 0..precision - digits + 1 {
+                for _ in 0..=precision - digits {
                     f.write_char('0')?;
                 }
             }
@@ -1969,7 +1969,7 @@ impl<S: Semantics> IeeeFloat<S> {
         // in a Limb. When this would overflow do we do a single
         // bignum multiplication, and then revert again to multiplication
         // in a Limb.
-        let mut chars = s[first_sig_digit..last_sig_digit + 1].chars();
+        let mut chars = s[first_sig_digit..=last_sig_digit].chars();
         loop {
             let mut val = 0;
             let mut multiplier = 1;

src/librustc_errors/emitter.rs

@@ -549,7 +549,7 @@ impl EmitterWriter {
         // 3 |
         // 4 |   }
         //   |
-        for pos in 0..line_len + 1 {
+        for pos in 0..=line_len {
             draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
             buffer.putc(line_offset + pos + 1,
                         width_offset - 2,
@@ -617,7 +617,7 @@ impl EmitterWriter {
             let pos = pos + 1;
 
             if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
-                for p in line_offset + 1..line_offset + pos + 1 {
+                for p in line_offset + 1..=line_offset + pos {
                     buffer.putc(p,
                                 code_offset + annotation.start_col,
                                 '|',
@@ -634,7 +634,7 @@ impl EmitterWriter {
                     }
                 }
                 AnnotationType::MultilineEnd(depth) => {
-                    for p in line_offset..line_offset + pos + 1 {
+                    for p in line_offset..=line_offset + pos {
                         buffer.putc(p,
                                     width_offset + depth - 1,
                                     '|',

src/librustc_incremental/persist/fs.rs

@@ -354,7 +354,7 @@ pub fn finalize_session_directory(sess: &Session, svh: Svh) {
     }
 
     // State: "s-{timestamp}-{random-number}-"
-    let mut new_sub_dir_name = String::from(&old_sub_dir_name[.. dash_indices[2] + 1]);
+    let mut new_sub_dir_name = String::from(&old_sub_dir_name[..= dash_indices[2]]);
 
     // Append the svh
     base_n::push_str(svh.as_u64() as u128, INT_ENCODE_BASE, &mut new_sub_dir_name);

src/librustc_mir/borrow_check/nll/region_infer/values.rs

@@ -48,7 +48,7 @@ impl RegionValueElements {
 
         let mut basic_blocks = IndexVec::with_capacity(num_points);
         for (bb, bb_data) in mir.basic_blocks().iter_enumerated() {
-            basic_blocks.extend((0..bb_data.statements.len() + 1).map(|_| bb));
+            basic_blocks.extend((0..=bb_data.statements.len()).map(|_| bb));
         }
 
         Self {

src/librustc_mir/build/matches/mod.rs

@@ -101,7 +101,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
 
         // create binding start block for link them by false edges
         let candidate_count = arms.iter().fold(0, |ac, c| ac + c.patterns.len());
-        let pre_binding_blocks: Vec<_> = (0..candidate_count + 1)
+        let pre_binding_blocks: Vec<_> = (0..=candidate_count)
             .map(|_| self.cfg.start_new_block())
             .collect();
 

src/librustc_resolve/lib.rs

@@ -3614,7 +3614,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
             let res = self.smart_resolve_path_fragment(
                 id,
                 None,
-                &path[..qself.position + 1],
+                &path[..=qself.position],
                 span,
                 PathSource::TraitItem(ns),
                 CrateLint::QPathTrait {

src/librustdoc/html/render.rs

@@ -4796,7 +4796,7 @@ impl<'a> fmt::Display for Source<'a> {
             tmp /= 10;
         }
         write!(fmt, "<pre class=\"line-numbers\">")?;
-        for i in 1..lines + 1 {
+        for i in 1..=lines {
             write!(fmt, "<span id=\"{0}\">{0:1$}</span>\n", i, cols)?;
         }
         write!(fmt, "</pre>")?;

src/libstd/collections/hash/map.rs

@@ -3610,7 +3610,7 @@ mod test_map {
             for i in 1..1001 {
                 assert!(m.insert(i, i).is_none());
 
-                for j in 1..i + 1 {
+                for j in 1..=i {
                     let r = m.get(&j);
                     assert_eq!(r, Some(&j));
                 }
@@ -3629,7 +3629,7 @@ mod test_map {
             for i in 1..1001 {
                 assert!(m.remove(&i).is_some());
 
-                for j in 1..i + 1 {
+                for j in 1..=i {
                     assert!(!m.contains_key(&j));
                 }
 

src/libstd/io/buffered.rs

@@ -918,7 +918,7 @@ impl<W: Write> Write for LineWriter<W> {
         // some data then we *must* report that we wrote that data, so future
         // errors are ignored. We set our internal `need_flush` flag, though, in
         // case flushing fails and we need to try it first next time.
-        let n = self.inner.write(&buf[..i + 1])?;
+        let n = self.inner.write(&buf[..=i])?;
         self.need_flush = true;
         if self.flush().is_err() || n != i + 1 {
             return Ok(n)

src/libstd/io/mod.rs

@@ -1261,7 +1261,7 @@ fn read_until<R: BufRead + ?Sized>(r: &mut R, delim: u8, buf: &mut Vec<u8>)
             };
             match memchr::memchr(delim, available) {
                 Some(i) => {
-                    buf.extend_from_slice(&available[..i + 1]);
+                    buf.extend_from_slice(&available[..=i]);
                     (true, i + 1)
                 }
                 None => {

src/libstd/sys/windows/process.rs

@@ -487,7 +487,7 @@ fn make_command_line(prog: &OsStr, args: &[OsString]) -> io::Result<Vec<u16>> {
             } else {
                 if x == '"' as u16 {
                     // Add n+1 backslashes to total 2n+1 before internal '"'.
-                    cmd.extend((0..(backslashes + 1)).map(|_| '\\' as u16));
+                    cmd.extend((0..=backslashes).map(|_| '\\' as u16));
                 }
                 backslashes = 0;
             }

src/libsyntax/util/lev_distance.rs

@@ -20,7 +20,7 @@ pub fn lev_distance(a: &str, b: &str) -> usize {
         return a.chars().count();
     }
 
-    let mut dcol: Vec<_> = (0..b.len() + 1).collect();
+    let mut dcol: Vec<_> = (0..=b.len()).collect();
     let mut t_last = 0;
 
     for (i, sc) in a.chars().enumerate() {