Adds #![deny(rust_2018_idioms)], applies lifetime elision suggestions (…

…#861)

benches/read_many_structs.rs

@@ -49,8 +49,7 @@ fn maximally_compact_1_1_data(num_values: usize) -> TestData_1_1 {
 
     let mut binary_1_1_data = vec![0xE0u8, 0x01, 0x01, 0xEA]; // IVM
     #[rustfmt::skip]
-    let mut binary_1_1_data_body: Vec<u8> = vec![
-        MacroTable::FIRST_USER_MACRO_ID as u8, // Macro ID
+    let mut binary_1_1_data_body: Vec<u8> = [MacroTable::FIRST_USER_MACRO_ID as u8, // Macro ID
         0b10, // [NOTE: `0b`] `parameters*` arg is an arg group
         0x66, // 6-byte integer (`timestamp` param)
         0x75, 0x5D, 0x63, 0xEE, 0x84, 0x01,
@@ -73,8 +72,7 @@ fn maximally_compact_1_1_data(num_values: usize) -> TestData_1_1 {
         0x32, 0x30, 0x3A, 0x35,
         0x39, 0x3A, 0x35, 0x39,
         0x2E, 0x37, 0x34, 0x34,
-        0x30, 0x30, 0x30, 0x5A,
-    ].repeat(num_values);
+        0x30, 0x30, 0x30, 0x5A].repeat(num_values);
     binary_1_1_data.append(&mut binary_1_1_data_body);
     TestData_1_1 {
         name: "maximally compact".to_owned(),
@@ -111,8 +109,7 @@ fn moderately_compact_1_1_data(num_values: usize) -> TestData_1_1 {
     let text_1_1_data = r#"(:event 1670446800245 418 "scheduler-thread-6" "example-client-1" "aws-us-east-5f-abc123" (: "region 4" "2022-12-07T20:59:59.744000Z"))"#.repeat(num_values);
     let mut binary_1_1_data = vec![0xE0u8, 0x01, 0x01, 0xEA]; // IVM
     #[rustfmt::skip]
-    let mut binary_1_1_data_body: Vec<u8> = vec![
-        MacroTable::FIRST_USER_MACRO_ID as u8, // Macro ID
+    let mut binary_1_1_data_body: Vec<u8> = [MacroTable::FIRST_USER_MACRO_ID as u8, // Macro ID
         0b10, // [NOTE: `0b` prefix] `parameters*` arg is an arg group
         0x66, // 6-byte integer (`timestamp` param)
         0x75, 0x5D, 0x63, 0xEE, 0x84, 0x01,
@@ -143,8 +140,7 @@ fn moderately_compact_1_1_data(num_values: usize) -> TestData_1_1 {
         0x32, 0x30, 0x3A, 0x35,
         0x39, 0x3A, 0x35, 0x39,
         0x2E, 0x37, 0x34, 0x34,
-        0x30, 0x30, 0x30, 0x5A,
-    ].repeat(num_values);
+        0x30, 0x30, 0x30, 0x5A].repeat(num_values);
 
     binary_1_1_data.append(&mut binary_1_1_data_body);
     TestData_1_1 {
@@ -182,8 +178,7 @@ fn length_prefixed_moderately_compact_1_1_data(num_values: usize) -> TestData_1_
     let text_1_1_data = r#"(:event 1670446800245 418 "scheduler-thread-6" "example-client-1" "aws-us-east-5f-abc123" (: "region 4" "2022-12-07T20:59:59.744000Z"))"#.repeat(num_values);
     let mut binary_1_1_data = vec![0xE0u8, 0x01, 0x01, 0xEA]; // IVM
     #[rustfmt::skip]
-    let mut binary_1_1_data_body: Vec<u8> = vec![
-        0xF5, // LP invocation
+    let mut binary_1_1_data_body: Vec<u8> = [0xF5, // LP invocation
         ((MacroTable::FIRST_USER_MACRO_ID * 2) + 1) as u8, // Macro ID
         0xDF, // Length prefix: FlexUInt 111
         0b10, // [NOTE: `0b` prefix] `parameters*` arg is an arg group
@@ -216,8 +211,7 @@ fn length_prefixed_moderately_compact_1_1_data(num_values: usize) -> TestData_1_
         0x32, 0x30, 0x3A, 0x35,
         0x39, 0x3A, 0x35, 0x39,
         0x2E, 0x37, 0x34, 0x34,
-        0x30, 0x30, 0x30, 0x5A,
-    ].repeat(num_values);
+        0x30, 0x30, 0x30, 0x5A].repeat(num_values);
 
     binary_1_1_data.append(&mut binary_1_1_data_body);
     TestData_1_1 {

benches/write_many_structs.rs

@@ -39,7 +39,7 @@ mod benchmark {
             // $16 = parameters
             .write(
                 16,
-                &[
+                [
                     black_box("SUCCESS"),
                     black_box("example-client-1"),
                     black_box("aws-us-east-5f-abc-123"),
@@ -68,7 +68,7 @@ mod benchmark {
             // $16 = parameters
             .write(
                 16,
-                &[
+                [
                     // $21 = SUCCESS
                     symbol_id(black_box(21)),
                     // $22 = example-client-1

examples/read_all_values.rs

@@ -21,7 +21,7 @@ mod lazy_reader_example {
     pub fn read_all_values() -> IonResult<()> {
         let args: Vec<String> = std::env::args().collect();
         let path = args.get(1).unwrap_or_else(|| {
-            eprintln!("USAGE:\n\n    {} [Binary Ion file]\n", args.get(0).unwrap());
+            eprintln!("USAGE:\n\n    {} [Binary Ion file]\n", args.first().unwrap());
             eprintln!("No mode was specified.");
             exit(1);
         });

examples/write_log_events.rs

@@ -29,10 +29,10 @@ mod example {
         // By default, this program deletes the encoded output before it ends. To keep the files
         // for further review, you can pass a `--keep-files`/`-k` flag.
         let args: Vec<String> = args().collect();
-        let keep_files_flag = match args.get(1).map(|a| a.as_str()) {
-            Some("--keep-files") | Some("-k") => true,
-            _ => false,
-        };
+        let keep_files_flag = matches!(
+            args.get(1).map(|a| a.as_str()),
+            Some("--keep-files") | Some("-k")
+        );
 
         // Create a set of Log4J-style statements that might appear in a typical program. These statements
         // have a fixed combination of (logger name, log level, format string) fields.
@@ -179,13 +179,13 @@ mod example {
     // field name/value pair. In the case of recurring strings, we take the liberty of writing
     // out symbol IDs instead of the full text; this silent type coercion from string to symbol
     // is technically data loss, but results in a much more compact encoding.
-    impl<'a, 'b> WriteAsIon for SerializeWithoutMacros<'a, 'b> {
+    impl WriteAsIon for SerializeWithoutMacros<'_, '_> {
         fn write_as_ion<V: ValueWriter>(&self, writer: V) -> IonResult<()> {
             let event = self.0;
             let mut struct_ = writer.struct_writer()?;
             struct_
                 //            v--- Each field name is a symbol ID
-                .write(10, &event.timestamp)?
+                .write(10, event.timestamp)?
                 .write(11, event.thread_id)?
                 .write(12, &event.thread_name)?
                 //                 v--- The fixed strings from the log statement are also SIDs
@@ -202,7 +202,7 @@ mod example {
     // behavior for the thread name.
     struct ThreadName<'a>(&'a str);
 
-    impl<'a> WriteAsIon for ThreadName<'a> {
+    impl WriteAsIon for ThreadName<'_> {
         fn write_as_ion<V: ValueWriter>(&self, writer: V) -> IonResult<()> {
             // ID 12 chosen arbitrarily, but aligns with Ion 1.0 encoding above
             let mut eexp = writer.eexp_writer(12)?;
@@ -213,11 +213,11 @@ mod example {
         }
     }
 
-    impl<'a, 'b> WriteAsIon for SerializeWithMacros<'a, 'b> {
+    impl WriteAsIon for SerializeWithMacros<'_, '_> {
         fn write_as_ion<V: ValueWriter>(&self, writer: V) -> IonResult<()> {
             let event = self.0;
             let mut eexp = writer.eexp_writer(event.statement.index)?;
-            eexp.write(&event.timestamp)?
+            eexp.write(event.timestamp)?
                 .write(event.thread_id)?
                 // Wrap the thread name in the `ThreadName` wrapper to change its serialization.
                 .write(ThreadName(&event.thread_name))?
@@ -246,28 +246,28 @@ mod example {
                 "Foo",
                 "DEBUG",
                 "Database heartbeat received after {} ms",
-                &[Int]
+                [Int]
             ),
             LogStatement::new(
                 1,
                 "Bar",
                 "INFO",
                 "Retrieved {} results from the '{}' table in {} ms",
-                &[Int, String, Int],
+                [Int, String, Int],
             ),
             LogStatement::new(
                 2,
                 "Baz",
                 "WARN",
                 "Query to the '{}' table took {} ms to execute, which is higher than the configured threshold",
-                &[String, Int],
+                [String, Int],
             ),
             LogStatement::new(
                 3,
                 "Quux",
                 "ERROR",
                 "Connection to database lost",
-                &[]
+                []
             ),
         ]
     }
@@ -287,8 +287,8 @@ mod example {
             .collect()
     }
 
-    fn generate_event<'rng, 'statements>(
-        rng: &'rng mut StdRng,
+    fn generate_event<'statements>(
+        rng: &mut StdRng,
         log_statements: &'statements [LogStatement],
         event_index: usize,
     ) -> LogEvent<'statements> {

src/element/annotations.rs

@@ -38,7 +38,7 @@ impl Annotations {
 
     /// Returns an [`Iterator`] that yields each of the [`Symbol`]s in this annotations
     /// sequence in order.
-    pub fn iter(&self) -> SymbolsIterator {
+    pub fn iter(&self) -> SymbolsIterator<'_> {
         SymbolsIterator::new(self.symbols.as_slice())
     }
 

src/element/reader.rs

@@ -75,7 +75,7 @@ pub struct ElementIterator<'a, R: ElementReader + ?Sized> {
     reader: &'a mut R,
 }
 
-impl<'a, R: ElementReader + ?Sized> Iterator for ElementIterator<'a, R> {
+impl<R: ElementReader + ?Sized> Iterator for ElementIterator<'_, R> {
     type Item = IonResult<Element>;
 
     fn next(&mut self) -> Option<Self::Item> {

src/lazy/any_encoding.rs

@@ -103,7 +103,7 @@ pub enum LazyRawAnyVersionMarkerKind<'top> {
     Binary_1_1(LazyRawBinaryVersionMarker_1_1<'top>),
 }
 
-impl<'top> LazyRawAnyVersionMarker<'top> {
+impl LazyRawAnyVersionMarker<'_> {
     pub fn encoding(&self) -> IonEncoding {
         use crate::lazy::any_encoding::LazyRawAnyVersionMarkerKind::*;
         match self.encoding {
@@ -127,7 +127,7 @@ impl<'top> HasSpan<'top> for LazyRawAnyVersionMarker<'top> {
     }
 }
 
-impl<'top> HasRange for LazyRawAnyVersionMarker<'top> {
+impl HasRange for LazyRawAnyVersionMarker<'_> {
     fn range(&self) -> Range<usize> {
         use LazyRawAnyVersionMarkerKind::*;
         match self.encoding {
@@ -240,7 +240,7 @@ impl<'top> HasSpan<'top> for LazyRawAnyEExpression<'top> {
     }
 }
 
-impl<'top> HasRange for LazyRawAnyEExpression<'top> {
+impl HasRange for LazyRawAnyEExpression<'_> {
     fn range(&self) -> Range<usize> {
         use LazyRawAnyEExpressionKind::*;
         match self.encoding {
@@ -286,7 +286,7 @@ pub enum AnyEExpArgGroupKind<'top> {
     Binary_1_1(BinaryEExpArgGroup<'top>),
 }
 
-impl<'top> AnyEExpArgGroupKind<'top> {
+impl AnyEExpArgGroupKind<'_> {
     fn encoding(&self) -> &ParameterEncoding {
         match self {
             AnyEExpArgGroupKind::Text_1_1(g) => g.encoding(),
@@ -295,7 +295,7 @@ impl<'top> AnyEExpArgGroupKind<'top> {
     }
 }
 
-impl<'top> HasRange for AnyEExpArgGroup<'top> {
+impl HasRange for AnyEExpArgGroup<'_> {
     fn range(&self) -> Range<usize> {
         match self.kind {
             AnyEExpArgGroupKind::Text_1_1(group) => group.range(),
@@ -445,7 +445,7 @@ pub struct LazyRawAnyReader<'data> {
     encoding_reader: RawReaderKind<'data>,
 }
 
-impl<'data> LazyRawAnyReader<'data> {
+impl LazyRawAnyReader<'_> {
     fn detect_encoding(data: &[u8]) -> IonEncoding {
         const BINARY_1_0_IVM: &[u8] = &[0xEA, 0x01, 0x00, 0xE0];
 
@@ -478,7 +478,7 @@ impl<'data> RawReaderKind<'data> {
         data: &'data [u8],
         stream_offset: usize,
         encoding_hint: IonEncoding,
-    ) -> RawReaderKind {
+    ) -> RawReaderKind<'data> {
         use IonEncoding::*;
         match encoding_hint {
             Text_1_0 => RawReaderKind::Text_1_0(LazyRawTextReader_1_0::resume_at_offset(
@@ -659,7 +659,7 @@ impl<'data> LazyRawReader<'data, AnyEncoding> for LazyRawAnyReader<'data> {
         }
 
         use RawReaderKind::*;
-        let item: LazyRawStreamItem<AnyEncoding> = match &mut self.encoding_reader {
+        let item: LazyRawStreamItem<'_, AnyEncoding> = match &mut self.encoding_reader {
             Text_1_0(r) => r.next(context)?.into(),
             Binary_1_0(r) => r.next()?.into(),
             Text_1_1(r) => r.next(context)?.into(),
@@ -1008,7 +1008,7 @@ impl<'top> HasSpan<'top> for LazyRawAnyValue<'top> {
     }
 }
 
-impl<'top> HasRange for LazyRawAnyValue<'top> {
+impl HasRange for LazyRawAnyValue<'_> {
     fn range(&self) -> Range<usize> {
         use LazyRawValueKind::*;
         match &self.encoding {
@@ -1490,7 +1490,7 @@ impl<'top> HasSpan<'top> for LazyRawAnyFieldName<'top> {
     }
 }
 
-impl<'top> HasRange for LazyRawAnyFieldName<'top> {
+impl HasRange for LazyRawAnyFieldName<'_> {
     fn range(&self) -> Range<usize> {
         use LazyRawFieldNameKind::*;
         match self.encoding {
@@ -1817,8 +1817,8 @@ mod tests {
     }
 
     fn expect_version_change(
-        context_ref: EncodingContextRef,
-        reader: &mut LazyRawAnyReader,
+        context_ref: EncodingContextRef<'_>,
+        reader: &mut LazyRawAnyReader<'_>,
         encoding_before: IonEncoding,
         encoding_after: IonEncoding,
     ) -> IonResult<()> {
@@ -1835,8 +1835,8 @@ mod tests {
     }
 
     fn expect_int(
-        context_ref: EncodingContextRef,
-        reader: &mut LazyRawAnyReader,
+        context_ref: EncodingContextRef<'_>,
+        reader: &mut LazyRawAnyReader<'_>,
         expected_encoding: IonEncoding,
         expected_int: i64,
     ) -> IonResult<()> {

src/lazy/binary/immutable_buffer.rs

@@ -42,7 +42,7 @@ pub struct BinaryBuffer<'a> {
     offset: usize,
 }
 
-impl<'a> Debug for BinaryBuffer<'a> {
+impl Debug for BinaryBuffer<'_> {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         write!(f, "BinaryBuffer {{")?;
         for byte in self.bytes().iter().take(16) {
@@ -57,11 +57,11 @@ pub(crate) type ParseResult<'a, T> = IonResult<(T, BinaryBuffer<'a>)>;
 impl<'a> BinaryBuffer<'a> {
     /// Constructs a new `BinaryBuffer` that wraps `data`.
     #[inline]
-    pub fn new(data: &[u8]) -> BinaryBuffer {
+    pub fn new(data: &[u8]) -> BinaryBuffer<'_> {
         Self::new_with_offset(data, 0)
     }
 
-    pub fn new_with_offset(data: &[u8], offset: usize) -> BinaryBuffer {
+    pub fn new_with_offset(data: &[u8], offset: usize) -> BinaryBuffer<'_> {
         BinaryBuffer { data, offset }
     }
 

src/lazy/binary/raw/sequence.rs

@@ -106,7 +106,7 @@ impl<'top> LazyRawBinarySequence_1_0<'top> {
     }
 }
 
-impl<'a, 'top> IntoIterator for &'a LazyRawBinarySequence_1_0<'top> {
+impl<'top> IntoIterator for &LazyRawBinarySequence_1_0<'top> {
     type Item = IonResult<LazyRawValueExpr<'top, BinaryEncoding_1_0>>;
     type IntoIter = RawBinarySequenceIterator_1_0<'top>;
 
@@ -115,7 +115,7 @@ impl<'a, 'top> IntoIterator for &'a LazyRawBinarySequence_1_0<'top> {
     }
 }
 
-impl<'a> Debug for LazyRawBinarySequence_1_0<'a> {
+impl Debug for LazyRawBinarySequence_1_0<'_> {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         match self.value.encoded_value.ion_type() {
             IonType::SExp => {

src/lazy/binary/raw/struct.rs

@@ -27,7 +27,7 @@ impl<'top> LazyRawBinaryStruct_1_0<'top> {
     }
 }
 
-impl<'a, 'top> IntoIterator for &'a LazyRawBinaryStruct_1_0<'top> {
+impl<'top> IntoIterator for &LazyRawBinaryStruct_1_0<'top> {
     type Item = IonResult<LazyRawFieldExpr<'top, BinaryEncoding_1_0>>;
     type IntoIter = RawBinaryStructIterator_1_0<'top>;
 
@@ -36,7 +36,7 @@ impl<'a, 'top> IntoIterator for &'a LazyRawBinaryStruct_1_0<'top> {
     }
 }
 
-impl<'top> Debug for LazyRawBinaryStruct_1_0<'top> {
+impl Debug for LazyRawBinaryStruct_1_0<'_> {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         write!(f, "{{")?;
         for field in self {
@@ -129,7 +129,7 @@ impl<'top> HasSpan<'top> for LazyRawBinaryFieldName_1_0<'top> {
     }
 }
 
-impl<'top> HasRange for LazyRawBinaryFieldName_1_0<'top> {
+impl HasRange for LazyRawBinaryFieldName_1_0<'_> {
     fn range(&self) -> Range<usize> {
         self.matched.range()
     }
@@ -157,7 +157,7 @@ mod tests {
         // occupy the specified input ranges.
         type FieldNameAndRange<'a> = (RawSymbolRef<'a>, Range<usize>);
         type FieldTest<'a> = (&'a [u8], &'a [FieldNameAndRange<'a>]);
-        let tests: &[FieldTest] = &[
+        let tests: &[FieldTest<'_>] = &[
             // (Ion input, expected ranges of the struct's field names)
             (
                 &[0xD2, 0x84, 0x80], // {name: ""}