From e64ed91a4ee0a6251e280f87c700d0d0cdd47b51 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Mon, 26 Sep 2022 07:47:01 -0500
Subject: [PATCH 1/6] feat(parser): Support From<&OsStr> types for
 `value_parser!`

Last time I tried this, I wasn't able to resolve the lifetime issues.  I
seemed to have gotten it working this time.

This came up in #4254.
---
 src/builder/value_parser.rs | 40 +++++++++++++++++++++++++++++++------
 1 file changed, 34 insertions(+), 6 deletions(-)

diff --git a/src/builder/value_parser.rs b/src/builder/value_parser.rs
index c5b97061..5a42b036 100644
--- a/src/builder/value_parser.rs
+++ b/src/builder/value_parser.rs
@@ -2040,7 +2040,7 @@ pub mod via_prelude {
         type Parser;
         fn value_parser(&self) -> Self::Parser;
     }
-    impl<P: ValueParserFactory> _ValueParserViaFactory for &&_AutoValueParser<P> {
+    impl<P: ValueParserFactory> _ValueParserViaFactory for &&&_AutoValueParser<P> {
         type Parser = P::Parser;
         fn value_parser(&self) -> Self::Parser {
             P::value_parser()
@@ -2054,7 +2054,7 @@ pub mod via_prelude {
         fn value_parser(&self) -> Self::Output;
     }
     impl<E: crate::ValueEnum + Clone + Send + Sync + 'static> _ValueParserViaValueEnum
-        for &_AutoValueParser<E>
+        for &&_AutoValueParser<E>
     {
         type Output = EnumValueParser<E>;
 
@@ -2063,6 +2063,27 @@ pub mod via_prelude {
         }
     }
 
+    #[doc(hidden)]
+    pub trait _ValueParserViaFromOsStr: private::_ValueParserViaFromOsStrSealed {
+        fn value_parser(&self) -> _AnonymousValueParser;
+    }
+    impl<FromOsStr> _ValueParserViaFromOsStr for &_AutoValueParser<FromOsStr>
+    where
+        FromOsStr:
+            for<'s> From<&'s std::ffi::OsStr> + std::any::Any + Clone + Send + Sync + 'static,
+    {
+        fn value_parser(&self) -> _AnonymousValueParser {
+            _AnonymousValueParser(
+                OsStringValueParser::new()
+                    .map(|s| {
+                        let output = FromOsStr::from(&s);
+                        output
+                    })
+                    .into(),
+            )
+        }
+    }
+
     #[doc(hidden)]
     pub trait _ValueParserViaFromStr: private::_ValueParserViaFromStrSealed {
         fn value_parser(&self) -> _AnonymousValueParser;
@@ -2088,6 +2109,7 @@ pub mod via_prelude {
 ///   - [Native types][ValueParser]: `bool`, `String`, `OsString`, `PathBuf`
 ///   - [Ranged numeric types][RangedI64ValueParser]: `u8`, `i8`, `u16`, `i16, `u32`, `i32`, `u64`, `i64`
 /// - [`ValueEnum` types][crate::ValueEnum]
+/// - [`From<&OsStr>` types][std::convert::From]
 /// - [`FromStr` types][std::str::FromStr], including usize, isize
 ///
 /// # Example
@@ -2155,7 +2177,7 @@ macro_rules! value_parser {
     ($name:ty) => {{
         use $crate::builder::via_prelude::*;
         let auto = $crate::builder::_AutoValueParser::<$name>::new();
-        (&&&auto).value_parser()
+        (&&&&auto).value_parser()
     }};
 }
 
@@ -2163,13 +2185,19 @@ mod private {
     use super::*;
 
     pub trait _ValueParserViaSelfSealed {}
-    impl<P: Into<ValueParser>> _ValueParserViaSelfSealed for &&&_AutoValueParser<P> {}
+    impl<P: Into<ValueParser>> _ValueParserViaSelfSealed for &&&&_AutoValueParser<P> {}
 
     pub trait _ValueParserViaFactorySealed {}
-    impl<P: ValueParserFactory> _ValueParserViaFactorySealed for &&_AutoValueParser<P> {}
+    impl<P: ValueParserFactory> _ValueParserViaFactorySealed for &&&_AutoValueParser<P> {}
 
     pub trait _ValueParserViaValueEnumSealed {}
-    impl<E: crate::ValueEnum> _ValueParserViaValueEnumSealed for &_AutoValueParser<E> {}
+    impl<E: crate::ValueEnum> _ValueParserViaValueEnumSealed for &&_AutoValueParser<E> {}
+
+    pub trait _ValueParserViaFromOsStrSealed {}
+    impl<FromOsStr> _ValueParserViaFromOsStrSealed for &_AutoValueParser<FromOsStr> where
+        FromOsStr: for<'s> From<&'s std::ffi::OsStr> + std::any::Any + Send + Sync + 'static
+    {
+    }
 
     pub trait _ValueParserViaFromStrSealed {}
     impl<FromStr> _ValueParserViaFromStrSealed for _AutoValueParser<FromStr>

From 9f49c0c63022e04c5218fb5f0ff89ce42cb3f62c Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Mon, 26 Sep 2022 09:12:47 -0500
Subject: [PATCH 2/6] feat(parser): Support From<OsString> for value_parser

---
 src/builder/value_parser.rs | 38 +++++++++++++++++++++++++++++++------
 1 file changed, 32 insertions(+), 6 deletions(-)

diff --git a/src/builder/value_parser.rs b/src/builder/value_parser.rs
index 5a42b036..c39f08c3 100644
--- a/src/builder/value_parser.rs
+++ b/src/builder/value_parser.rs
@@ -2040,7 +2040,7 @@ pub mod via_prelude {
         type Parser;
         fn value_parser(&self) -> Self::Parser;
     }
-    impl<P: ValueParserFactory> _ValueParserViaFactory for &&&_AutoValueParser<P> {
+    impl<P: ValueParserFactory> _ValueParserViaFactory for &&&&_AutoValueParser<P> {
         type Parser = P::Parser;
         fn value_parser(&self) -> Self::Parser {
             P::value_parser()
@@ -2054,7 +2054,7 @@ pub mod via_prelude {
         fn value_parser(&self) -> Self::Output;
     }
     impl<E: crate::ValueEnum + Clone + Send + Sync + 'static> _ValueParserViaValueEnum
-        for &&_AutoValueParser<E>
+        for &&&_AutoValueParser<E>
     {
         type Output = EnumValueParser<E>;
 
@@ -2063,6 +2063,26 @@ pub mod via_prelude {
         }
     }
 
+    #[doc(hidden)]
+    pub trait _ValueParserViaFromOsString: private::_ValueParserViaFromOsStringSealed {
+        fn value_parser(&self) -> _AnonymousValueParser;
+    }
+    impl<FromOsString> _ValueParserViaFromOsString for &&_AutoValueParser<FromOsString>
+    where
+        FromOsString: From<std::ffi::OsString> + std::any::Any + Clone + Send + Sync + 'static,
+    {
+        fn value_parser(&self) -> _AnonymousValueParser {
+            _AnonymousValueParser(
+                OsStringValueParser::new()
+                    .map(|s| {
+                        let output = FromOsString::from(s);
+                        output
+                    })
+                    .into(),
+            )
+        }
+    }
+
     #[doc(hidden)]
     pub trait _ValueParserViaFromOsStr: private::_ValueParserViaFromOsStrSealed {
         fn value_parser(&self) -> _AnonymousValueParser;
@@ -2109,7 +2129,7 @@ pub mod via_prelude {
 ///   - [Native types][ValueParser]: `bool`, `String`, `OsString`, `PathBuf`
 ///   - [Ranged numeric types][RangedI64ValueParser]: `u8`, `i8`, `u16`, `i16, `u32`, `i32`, `u64`, `i64`
 /// - [`ValueEnum` types][crate::ValueEnum]
-/// - [`From<&OsStr>` types][std::convert::From]
+/// - [`From<&OsString>` types][std::convert::From] and [`From<&OsStr>` types][std::convert::From]
 /// - [`FromStr` types][std::str::FromStr], including usize, isize
 ///
 /// # Example
@@ -2185,13 +2205,19 @@ mod private {
     use super::*;
 
     pub trait _ValueParserViaSelfSealed {}
-    impl<P: Into<ValueParser>> _ValueParserViaSelfSealed for &&&&_AutoValueParser<P> {}
+    impl<P: Into<ValueParser>> _ValueParserViaSelfSealed for &&&&&_AutoValueParser<P> {}
 
     pub trait _ValueParserViaFactorySealed {}
-    impl<P: ValueParserFactory> _ValueParserViaFactorySealed for &&&_AutoValueParser<P> {}
+    impl<P: ValueParserFactory> _ValueParserViaFactorySealed for &&&&_AutoValueParser<P> {}
 
     pub trait _ValueParserViaValueEnumSealed {}
-    impl<E: crate::ValueEnum> _ValueParserViaValueEnumSealed for &&_AutoValueParser<E> {}
+    impl<E: crate::ValueEnum> _ValueParserViaValueEnumSealed for &&&_AutoValueParser<E> {}
+
+    pub trait _ValueParserViaFromOsStringSealed {}
+    impl<FromOsString> _ValueParserViaFromOsStringSealed for &&_AutoValueParser<FromOsString> where
+        FromOsString: From<std::ffi::OsString> + std::any::Any + Send + Sync + 'static
+    {
+    }
 
     pub trait _ValueParserViaFromOsStrSealed {}
     impl<FromOsStr> _ValueParserViaFromOsStrSealed for &_AutoValueParser<FromOsStr> where

From 76ec238b455945eca5600f5cb56984ccf2383ad7 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Mon, 26 Sep 2022 09:14:39 -0500
Subject: [PATCH 3/6] docs: Clarify value_parser implementation

---
 src/builder/value_parser.rs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/builder/value_parser.rs b/src/builder/value_parser.rs
index c39f08c3..3f61433b 100644
--- a/src/builder/value_parser.rs
+++ b/src/builder/value_parser.rs
@@ -1930,25 +1930,25 @@ pub trait ValueParserFactory {
 impl ValueParserFactory for String {
     type Parser = ValueParser;
     fn value_parser() -> Self::Parser {
-        ValueParser::string()
+        ValueParser::string() // Default `clap_derive` to optimized implementation
     }
 }
 impl ValueParserFactory for std::ffi::OsString {
     type Parser = ValueParser;
     fn value_parser() -> Self::Parser {
-        ValueParser::os_string()
+        ValueParser::os_string() // Default `clap_derive` to optimized implementation
     }
 }
 impl ValueParserFactory for std::path::PathBuf {
     type Parser = ValueParser;
     fn value_parser() -> Self::Parser {
-        ValueParser::path_buf()
+        ValueParser::path_buf() // Default `clap_derive` to optimized implementation
     }
 }
 impl ValueParserFactory for bool {
     type Parser = ValueParser;
     fn value_parser() -> Self::Parser {
-        ValueParser::bool()
+        ValueParser::bool() // Default `clap_derive` to optimized implementation
     }
 }
 impl ValueParserFactory for u8 {
@@ -2204,6 +2204,7 @@ macro_rules! value_parser {
 mod private {
     use super::*;
 
+    // Prefer these so `clap_derive` defaults to optimized implementations
     pub trait _ValueParserViaSelfSealed {}
     impl<P: Into<ValueParser>> _ValueParserViaSelfSealed for &&&&&_AutoValueParser<P> {}
 

From 931b6338f1258a12df29bfc8dbb3c5e839295258 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Mon, 26 Sep 2022 09:18:39 -0500
Subject: [PATCH 4/6] refactor(parser): Clarify FromStr from future FromStr

---
 src/builder/value_parser.rs | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/src/builder/value_parser.rs b/src/builder/value_parser.rs
index 3f61433b..cfbfc238 100644
--- a/src/builder/value_parser.rs
+++ b/src/builder/value_parser.rs
@@ -2105,18 +2105,17 @@ pub mod via_prelude {
     }
 
     #[doc(hidden)]
-    pub trait _ValueParserViaFromStr: private::_ValueParserViaFromStrSealed {
+    pub trait _ValueParserViaParse: private::_ValueParserViaParseSealed {
         fn value_parser(&self) -> _AnonymousValueParser;
     }
-    impl<FromStr> _ValueParserViaFromStr for _AutoValueParser<FromStr>
+    impl<Parse> _ValueParserViaParse for _AutoValueParser<Parse>
     where
-        FromStr: std::str::FromStr + std::any::Any + Clone + Send + Sync + 'static,
-        <FromStr as std::str::FromStr>::Err:
-            Into<Box<dyn std::error::Error + Send + Sync + 'static>>,
+        Parse: std::str::FromStr + std::any::Any + Clone + Send + Sync + 'static,
+        <Parse as std::str::FromStr>::Err: Into<Box<dyn std::error::Error + Send + Sync + 'static>>,
     {
         fn value_parser(&self) -> _AnonymousValueParser {
-            let func: fn(&str) -> Result<FromStr, <FromStr as std::str::FromStr>::Err> =
-                FromStr::from_str;
+            let func: fn(&str) -> Result<Parse, <Parse as std::str::FromStr>::Err> =
+                Parse::from_str;
             _AnonymousValueParser(ValueParser::new(func))
         }
     }
@@ -2226,12 +2225,11 @@ mod private {
     {
     }
 
-    pub trait _ValueParserViaFromStrSealed {}
-    impl<FromStr> _ValueParserViaFromStrSealed for _AutoValueParser<FromStr>
+    pub trait _ValueParserViaParseSealed {}
+    impl<Parse> _ValueParserViaParseSealed for _AutoValueParser<Parse>
     where
-        FromStr: std::str::FromStr + std::any::Any + Send + Sync + 'static,
-        <FromStr as std::str::FromStr>::Err:
-            Into<Box<dyn std::error::Error + Send + Sync + 'static>>,
+        Parse: std::str::FromStr + std::any::Any + Send + Sync + 'static,
+        <Parse as std::str::FromStr>::Err: Into<Box<dyn std::error::Error + Send + Sync + 'static>>,
     {
     }
 }

From 31f9234cc7e608dc77c501a224596a22b48144a5 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Mon, 26 Sep 2022 09:22:41 -0500
Subject: [PATCH 5/6] feat(parser): Add From<str> and From<String>

---
 src/builder/value_parser.rs | 73 ++++++++++++++++++++++++++++++++-----
 1 file changed, 63 insertions(+), 10 deletions(-)

diff --git a/src/builder/value_parser.rs b/src/builder/value_parser.rs
index cfbfc238..5d70f2fb 100644
--- a/src/builder/value_parser.rs
+++ b/src/builder/value_parser.rs
@@ -2040,7 +2040,7 @@ pub mod via_prelude {
         type Parser;
         fn value_parser(&self) -> Self::Parser;
     }
-    impl<P: ValueParserFactory> _ValueParserViaFactory for &&&&_AutoValueParser<P> {
+    impl<P: ValueParserFactory> _ValueParserViaFactory for &&&&&&_AutoValueParser<P> {
         type Parser = P::Parser;
         fn value_parser(&self) -> Self::Parser {
             P::value_parser()
@@ -2054,7 +2054,7 @@ pub mod via_prelude {
         fn value_parser(&self) -> Self::Output;
     }
     impl<E: crate::ValueEnum + Clone + Send + Sync + 'static> _ValueParserViaValueEnum
-        for &&&_AutoValueParser<E>
+        for &&&&&_AutoValueParser<E>
     {
         type Output = EnumValueParser<E>;
 
@@ -2067,7 +2067,7 @@ pub mod via_prelude {
     pub trait _ValueParserViaFromOsString: private::_ValueParserViaFromOsStringSealed {
         fn value_parser(&self) -> _AnonymousValueParser;
     }
-    impl<FromOsString> _ValueParserViaFromOsString for &&_AutoValueParser<FromOsString>
+    impl<FromOsString> _ValueParserViaFromOsString for &&&&_AutoValueParser<FromOsString>
     where
         FromOsString: From<std::ffi::OsString> + std::any::Any + Clone + Send + Sync + 'static,
     {
@@ -2087,7 +2087,7 @@ pub mod via_prelude {
     pub trait _ValueParserViaFromOsStr: private::_ValueParserViaFromOsStrSealed {
         fn value_parser(&self) -> _AnonymousValueParser;
     }
-    impl<FromOsStr> _ValueParserViaFromOsStr for &_AutoValueParser<FromOsStr>
+    impl<FromOsStr> _ValueParserViaFromOsStr for &&&_AutoValueParser<FromOsStr>
     where
         FromOsStr:
             for<'s> From<&'s std::ffi::OsStr> + std::any::Any + Clone + Send + Sync + 'static,
@@ -2104,6 +2104,46 @@ pub mod via_prelude {
         }
     }
 
+    #[doc(hidden)]
+    pub trait _ValueParserViaFromString: private::_ValueParserViaFromStringSealed {
+        fn value_parser(&self) -> _AnonymousValueParser;
+    }
+    impl<FromString> _ValueParserViaFromString for &&_AutoValueParser<FromString>
+    where
+        FromString: From<String> + std::any::Any + Clone + Send + Sync + 'static,
+    {
+        fn value_parser(&self) -> _AnonymousValueParser {
+            _AnonymousValueParser(
+                StringValueParser::new()
+                    .map(|s| {
+                        let output = FromString::from(s);
+                        output
+                    })
+                    .into(),
+            )
+        }
+    }
+
+    #[doc(hidden)]
+    pub trait _ValueParserViaFromStr: private::_ValueParserViaFromStrSealed {
+        fn value_parser(&self) -> _AnonymousValueParser;
+    }
+    impl<FromStr> _ValueParserViaFromStr for &_AutoValueParser<FromStr>
+    where
+        FromStr: for<'s> From<&'s str> + std::any::Any + Clone + Send + Sync + 'static,
+    {
+        fn value_parser(&self) -> _AnonymousValueParser {
+            _AnonymousValueParser(
+                StringValueParser::new()
+                    .map(|s| {
+                        let output = FromStr::from(&s);
+                        output
+                    })
+                    .into(),
+            )
+        }
+    }
+
     #[doc(hidden)]
     pub trait _ValueParserViaParse: private::_ValueParserViaParseSealed {
         fn value_parser(&self) -> _AnonymousValueParser;
@@ -2129,6 +2169,7 @@ pub mod via_prelude {
 ///   - [Ranged numeric types][RangedI64ValueParser]: `u8`, `i8`, `u16`, `i16, `u32`, `i32`, `u64`, `i64`
 /// - [`ValueEnum` types][crate::ValueEnum]
 /// - [`From<&OsString>` types][std::convert::From] and [`From<&OsStr>` types][std::convert::From]
+/// - [`From<&String>` types][std::convert::From] and [`From<&str>` types][std::convert::From]
 /// - [`FromStr` types][std::str::FromStr], including usize, isize
 ///
 /// # Example
@@ -2196,7 +2237,7 @@ macro_rules! value_parser {
     ($name:ty) => {{
         use $crate::builder::via_prelude::*;
         let auto = $crate::builder::_AutoValueParser::<$name>::new();
-        (&&&&auto).value_parser()
+        (&&&&&&auto).value_parser()
     }};
 }
 
@@ -2205,26 +2246,38 @@ mod private {
 
     // Prefer these so `clap_derive` defaults to optimized implementations
     pub trait _ValueParserViaSelfSealed {}
-    impl<P: Into<ValueParser>> _ValueParserViaSelfSealed for &&&&&_AutoValueParser<P> {}
+    impl<P: Into<ValueParser>> _ValueParserViaSelfSealed for &&&&&&&_AutoValueParser<P> {}
 
     pub trait _ValueParserViaFactorySealed {}
-    impl<P: ValueParserFactory> _ValueParserViaFactorySealed for &&&&_AutoValueParser<P> {}
+    impl<P: ValueParserFactory> _ValueParserViaFactorySealed for &&&&&&_AutoValueParser<P> {}
 
     pub trait _ValueParserViaValueEnumSealed {}
-    impl<E: crate::ValueEnum> _ValueParserViaValueEnumSealed for &&&_AutoValueParser<E> {}
+    impl<E: crate::ValueEnum> _ValueParserViaValueEnumSealed for &&&&&_AutoValueParser<E> {}
 
     pub trait _ValueParserViaFromOsStringSealed {}
-    impl<FromOsString> _ValueParserViaFromOsStringSealed for &&_AutoValueParser<FromOsString> where
+    impl<FromOsString> _ValueParserViaFromOsStringSealed for &&&&_AutoValueParser<FromOsString> where
         FromOsString: From<std::ffi::OsString> + std::any::Any + Send + Sync + 'static
     {
     }
 
     pub trait _ValueParserViaFromOsStrSealed {}
-    impl<FromOsStr> _ValueParserViaFromOsStrSealed for &_AutoValueParser<FromOsStr> where
+    impl<FromOsStr> _ValueParserViaFromOsStrSealed for &&&_AutoValueParser<FromOsStr> where
         FromOsStr: for<'s> From<&'s std::ffi::OsStr> + std::any::Any + Send + Sync + 'static
     {
     }
 
+    pub trait _ValueParserViaFromStringSealed {}
+    impl<FromString> _ValueParserViaFromStringSealed for &&_AutoValueParser<FromString> where
+        FromString: From<String> + std::any::Any + Send + Sync + 'static
+    {
+    }
+
+    pub trait _ValueParserViaFromStrSealed {}
+    impl<FromStr> _ValueParserViaFromStrSealed for &_AutoValueParser<FromStr> where
+        FromStr: for<'s> From<&'s str> + std::any::Any + Send + Sync + 'static
+    {
+    }
+
     pub trait _ValueParserViaParseSealed {}
     impl<Parse> _ValueParserViaParseSealed for _AutoValueParser<Parse>
     where

From bd6b67c60505ce13e447d65e5323d4633655ce91 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Mon, 26 Sep 2022 09:55:02 -0500
Subject: [PATCH 6/6] style: Make clippy happy

---
 src/builder/str.rs          |  2 +-
 src/builder/value_parser.rs | 28 ++++------------------------
 2 files changed, 5 insertions(+), 25 deletions(-)

diff --git a/src/builder/str.rs b/src/builder/str.rs
index 8dd9a7f4..e4750c74 100644
--- a/src/builder/str.rs
+++ b/src/builder/str.rs
@@ -131,7 +131,7 @@ impl AsRef<[u8]> for Str {
 impl AsRef<std::ffi::OsStr> for Str {
     #[inline]
     fn as_ref(&self) -> &std::ffi::OsStr {
-        (&**self).as_ref()
+        (**self).as_ref()
     }
 }
 
diff --git a/src/builder/value_parser.rs b/src/builder/value_parser.rs
index 5d70f2fb..8a5ae1be 100644
--- a/src/builder/value_parser.rs
+++ b/src/builder/value_parser.rs
@@ -2074,10 +2074,7 @@ pub mod via_prelude {
         fn value_parser(&self) -> _AnonymousValueParser {
             _AnonymousValueParser(
                 OsStringValueParser::new()
-                    .map(|s| {
-                        let output = FromOsString::from(s);
-                        output
-                    })
+                    .map(|s| FromOsString::from(s))
                     .into(),
             )
         }
@@ -2095,10 +2092,7 @@ pub mod via_prelude {
         fn value_parser(&self) -> _AnonymousValueParser {
             _AnonymousValueParser(
                 OsStringValueParser::new()
-                    .map(|s| {
-                        let output = FromOsStr::from(&s);
-                        output
-                    })
+                    .map(|s| FromOsStr::from(&s))
                     .into(),
             )
         }
@@ -2113,14 +2107,7 @@ pub mod via_prelude {
         FromString: From<String> + std::any::Any + Clone + Send + Sync + 'static,
     {
         fn value_parser(&self) -> _AnonymousValueParser {
-            _AnonymousValueParser(
-                StringValueParser::new()
-                    .map(|s| {
-                        let output = FromString::from(s);
-                        output
-                    })
-                    .into(),
-            )
+            _AnonymousValueParser(StringValueParser::new().map(|s| FromString::from(s)).into())
         }
     }
 
@@ -2133,14 +2120,7 @@ pub mod via_prelude {
         FromStr: for<'s> From<&'s str> + std::any::Any + Clone + Send + Sync + 'static,
     {
         fn value_parser(&self) -> _AnonymousValueParser {
-            _AnonymousValueParser(
-                StringValueParser::new()
-                    .map(|s| {
-                        let output = FromStr::from(&s);
-                        output
-                    })
-                    .into(),
-            )
+            _AnonymousValueParser(StringValueParser::new().map(|s| FromStr::from(&s)).into())
         }
     }