Fix some Clippy warnings (#356)

* fix collapsible if warning

* remove needlees return

* substitute write! to writeln!

* remove redundant field names in struct initialization

* add non exhaustive attribute in all enums in handler.rs

* fix inconsistent digit grouping

* simplify return of extra_description method

* fix zero pointer

curl-sys/build.rs

@@ -23,21 +23,19 @@ fn main() {
     if !cfg!(feature = "static-curl") {
         // OSX and Haiku ships libcurl by default, so we just use that version
         // so long as it has the right features enabled.
-        if target.contains("apple") || target.contains("haiku") {
-            if !cfg!(feature = "http2") || curl_config_reports_http2() {
-                return println!("cargo:rustc-flags=-l curl");
-            }
+        if (target.contains("apple") || target.contains("haiku"))
+            && (!cfg!(feature = "http2") || curl_config_reports_http2())
+        {
+            return println!("cargo:rustc-flags=-l curl");
         }
 
         // Next, fall back and try to use pkg-config if its available.
         if windows {
             if try_vcpkg() {
                 return;
             }
-        } else {
-            if try_pkg_config() {
-                return;
-            }
+        } else if try_pkg_config() {
+            return;
         }
     }
 
@@ -468,7 +466,7 @@ fn try_pkg_config() -> bool {
     for path in lib.include_paths.iter() {
         println!("cargo:include={}", path.display());
     }
-    return true;
+    true
 }
 
 fn xcode_major_version() -> Option<u8> {
@@ -508,7 +506,7 @@ fn curl_config_reports_http2() -> bool {
         return false;
     }
 
-    return true;
+    true
 }
 
 fn macos_link_search_path() -> Option<String> {

src/easy/form.rs

@@ -1,6 +1,7 @@
 use std::ffi::CString;
 use std::fmt;
 use std::path::Path;
+use std::ptr;
 
 use curl_sys;
 use easy::{list, List};
@@ -34,8 +35,8 @@ impl Form {
     /// Creates a new blank form ready for the addition of new data.
     pub fn new() -> Form {
         Form {
-            head: 0 as *mut _,
-            tail: 0 as *mut _,
+            head: ptr::null_mut(),
+            tail: ptr::null_mut(),
             headers: Vec::new(),
             buffers: Vec::new(),
             strings: Vec::new(),
@@ -50,10 +51,10 @@ impl Form {
         Part {
             error: None,
             form: self,
-            name: name,
+            name,
             array: vec![curl_sys::curl_forms {
                 option: curl_sys::CURLFORM_END,
-                value: 0 as *mut _,
+                value: ptr::null_mut(),
             }],
         }
     }

src/easy/handler.rs

@@ -3,6 +3,7 @@ use std::ffi::{CStr, CString};
 use std::fmt;
 use std::io::{self, SeekFrom, Write};
 use std::path::Path;
+use std::ptr;
 use std::slice;
 use std::str;
 use std::time::Duration;
@@ -306,13 +307,12 @@ pub fn debug(kind: InfoType, data: &[u8]) {
         InfoType::HeaderOut => ">",
         InfoType::DataIn | InfoType::SslDataIn => "{",
         InfoType::DataOut | InfoType::SslDataOut => "}",
-        InfoType::__Nonexhaustive => " ",
     };
     let mut out = out.lock();
     drop(write!(out, "{} ", prefix));
     match str::from_utf8(data) {
         Ok(s) => drop(out.write_all(s.as_bytes())),
-        Err(_) => drop(write!(out, "({} bytes of data)\n", data.len())),
+        Err(_) => drop(writeln!(out, "({} bytes of data)", data.len())),
     }
 }
 
@@ -392,6 +392,7 @@ struct Inner<H> {
 unsafe impl<H: Send> Send for Inner<H> {}
 
 /// Possible proxy types that libcurl currently understands.
+#[non_exhaustive]
 #[allow(missing_docs)]
 #[derive(Debug, Clone, Copy)]
 pub enum ProxyType {
@@ -401,43 +402,31 @@ pub enum ProxyType {
     Socks5 = curl_sys::CURLPROXY_SOCKS5 as isize,
     Socks4a = curl_sys::CURLPROXY_SOCKS4A as isize,
     Socks5Hostname = curl_sys::CURLPROXY_SOCKS5_HOSTNAME as isize,
-
-    /// Hidden variant to indicate that this enum should not be matched on, it
-    /// may grow over time.
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
 /// Possible conditions for the `time_condition` method.
+#[non_exhaustive]
 #[allow(missing_docs)]
 #[derive(Debug, Clone, Copy)]
 pub enum TimeCondition {
     None = curl_sys::CURL_TIMECOND_NONE as isize,
     IfModifiedSince = curl_sys::CURL_TIMECOND_IFMODSINCE as isize,
     IfUnmodifiedSince = curl_sys::CURL_TIMECOND_IFUNMODSINCE as isize,
     LastModified = curl_sys::CURL_TIMECOND_LASTMOD as isize,
-
-    /// Hidden variant to indicate that this enum should not be matched on, it
-    /// may grow over time.
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
 /// Possible values to pass to the `ip_resolve` method.
+#[non_exhaustive]
 #[allow(missing_docs)]
 #[derive(Debug, Clone, Copy)]
 pub enum IpResolve {
     V4 = curl_sys::CURL_IPRESOLVE_V4 as isize,
     V6 = curl_sys::CURL_IPRESOLVE_V6 as isize,
     Any = curl_sys::CURL_IPRESOLVE_WHATEVER as isize,
-
-    /// Hidden variant to indicate that this enum should not be matched on, it
-    /// may grow over time.
-    #[doc(hidden)]
-    __Nonexhaustive = 500,
 }
 
 /// Possible values to pass to the `http_version` method.
+#[non_exhaustive]
 #[derive(Debug, Clone, Copy)]
 pub enum HttpVersion {
     /// We don't care what http version to use, and we'd like the library to
@@ -472,14 +461,10 @@ pub enum HttpVersion {
     ///
     /// (Added in CURL 7.66.0)
     V3 = curl_sys::CURL_HTTP_VERSION_3 as isize,
-
-    /// Hidden variant to indicate that this enum should not be matched on, it
-    /// may grow over time.
-    #[doc(hidden)]
-    __Nonexhaustive = 500,
 }
 
 /// Possible values to pass to the `ssl_version` and `ssl_min_max_version` method.
+#[non_exhaustive]
 #[allow(missing_docs)]
 #[derive(Debug, Clone, Copy)]
 pub enum SslVersion {
@@ -491,14 +476,10 @@ pub enum SslVersion {
     Tlsv11 = curl_sys::CURL_SSLVERSION_TLSv1_1 as isize,
     Tlsv12 = curl_sys::CURL_SSLVERSION_TLSv1_2 as isize,
     Tlsv13 = curl_sys::CURL_SSLVERSION_TLSv1_3 as isize,
-
-    /// Hidden variant to indicate that this enum should not be matched on, it
-    /// may grow over time.
-    #[doc(hidden)]
-    __Nonexhaustive = 500,
 }
 
 /// Possible return values from the `seek_function` callback.
+#[non_exhaustive]
 #[derive(Debug, Clone, Copy)]
 pub enum SeekResult {
     /// Indicates that the seek operation was a success
@@ -511,15 +492,11 @@ pub enum SeekResult {
     /// Indicates that although the seek failed libcurl should attempt to keep
     /// working if possible (for example "seek" through reading).
     CantSeek = curl_sys::CURL_SEEKFUNC_CANTSEEK as isize,
-
-    /// Hidden variant to indicate that this enum should not be matched on, it
-    /// may grow over time.
-    #[doc(hidden)]
-    __Nonexhaustive = 500,
 }
 
 /// Possible data chunks that can be witnessed as part of the `debug_function`
 /// callback.
+#[non_exhaustive]
 #[derive(Debug, Clone, Copy)]
 pub enum InfoType {
     /// The data is informational text.
@@ -542,38 +519,25 @@ pub enum InfoType {
 
     /// The data is SSL/TLS (binary) data sent to the peer.
     SslDataOut,
-
-    /// Hidden variant to indicate that this enum should not be matched on, it
-    /// may grow over time.
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
 /// Possible error codes that can be returned from the `read_function` callback.
+#[non_exhaustive]
 #[derive(Debug)]
 pub enum ReadError {
     /// Indicates that the connection should be aborted immediately
     Abort,
 
     /// Indicates that reading should be paused until `unpause` is called.
     Pause,
-
-    /// Hidden variant to indicate that this enum should not be matched on, it
-    /// may grow over time.
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
 /// Possible error codes that can be returned from the `write_function` callback.
+#[non_exhaustive]
 #[derive(Debug)]
 pub enum WriteError {
     /// Indicates that reading should be paused until `unpause` is called.
     Pause,
-
-    /// Hidden variant to indicate that this enum should not be matched on, it
-    /// may grow over time.
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
 /// Options for `.netrc` parsing.
@@ -623,17 +587,17 @@ impl<H: Handler> Easy2<H> {
             assert!(!handle.is_null());
             let mut ret = Easy2 {
                 inner: Box::new(Inner {
-                    handle: handle,
+                    handle,
                     header_list: None,
                     resolve_list: None,
                     connect_to_list: None,
                     form: None,
                     error_buf: RefCell::new(vec![0; curl_sys::CURL_ERROR_SIZE]),
-                    handler: handler,
+                    handler,
                 }),
             };
             ret.default_configure();
-            return ret;
+            ret
         }
     }
 
@@ -2658,7 +2622,7 @@ impl<H> Easy2<H> {
     /// if the option isn't supported.
     pub fn cookies(&mut self) -> Result<List, Error> {
         unsafe {
-            let mut list = 0 as *mut _;
+            let mut list = ptr::null_mut();
             let rc = curl_sys::curl_easy_getinfo(
                 self.inner.handle,
                 curl_sys::CURLINFO_COOKIELIST,
@@ -2721,7 +2685,7 @@ impl<H> Easy2<H> {
     pub fn perform(&self) -> Result<(), Error> {
         let ret = unsafe { self.cvt(curl_sys::curl_easy_perform(self.inner.handle)) };
         panic::propagate();
-        return ret;
+        ret
     }
 
     /// Unpause reading on a connection.
@@ -2781,7 +2745,7 @@ impl<H> Easy2<H> {
             let ret = str::from_utf8(CStr::from_ptr(p).to_bytes()).unwrap();
             let ret = String::from(ret);
             curl_sys::curl_free(p as *mut _);
-            return ret;
+            ret
         }
     }
 
@@ -2815,7 +2779,7 @@ impl<H> Easy2<H> {
             let slice = slice::from_raw_parts(p as *const u8, len as usize);
             let ret = slice.to_vec();
             curl_sys::curl_free(p as *mut _);
-            return ret;
+            ret
         }
     }
 
@@ -3060,9 +3024,7 @@ extern "C" fn write_cb<H: Handler>(
         let input = slice::from_raw_parts(ptr as *const u8, size * nmemb);
         match (*(data as *mut Inner<H>)).handler.write(input) {
             Ok(s) => s,
-            Err(WriteError::Pause) | Err(WriteError::__Nonexhaustive) => {
-                curl_sys::CURL_WRITEFUNC_PAUSE
-            }
+            Err(WriteError::Pause) => curl_sys::CURL_WRITEFUNC_PAUSE,
         }
     })
     .unwrap_or(!0)
@@ -3079,9 +3041,7 @@ extern "C" fn read_cb<H: Handler>(
         match (*(data as *mut Inner<H>)).handler.read(input) {
             Ok(s) => s,
             Err(ReadError::Pause) => curl_sys::CURL_READFUNC_PAUSE,
-            Err(ReadError::__Nonexhaustive) | Err(ReadError::Abort) => {
-                curl_sys::CURL_READFUNC_ABORT
-            }
+            Err(ReadError::Abort) => curl_sys::CURL_READFUNC_ABORT,
         }
     })
     .unwrap_or(!0)
@@ -3145,7 +3105,7 @@ extern "C" fn debug_cb<H: Handler>(
         };
         (*(userptr as *mut Inner<H>)).handler.debug(kind, data)
     });
-    return 0;
+    0
 }
 
 extern "C" fn ssl_ctx_cb<H: Handler>(

src/easy/list.rs

@@ -1,5 +1,6 @@
 use std::ffi::{CStr, CString};
 use std::fmt;
+use std::ptr;
 
 use curl_sys;
 use Error;
@@ -21,15 +22,17 @@ pub fn raw(list: &List) -> *mut curl_sys::curl_slist {
 }
 
 pub unsafe fn from_raw(raw: *mut curl_sys::curl_slist) -> List {
-    List { raw: raw }
+    List { raw }
 }
 
 unsafe impl Send for List {}
 
 impl List {
     /// Creates a new empty list of strings.
     pub fn new() -> List {
-        List { raw: 0 as *mut _ }
+        List {
+            raw: ptr::null_mut(),
+        }
     }
 
     /// Appends some data into this list.
@@ -86,7 +89,7 @@ impl<'a> Iterator for Iter<'a> {
         unsafe {
             let ret = Some(CStr::from_ptr((*self.cur).data).to_bytes());
             self.cur = (*self.cur).next;
-            return ret;
+            ret
         }
     }
 }