There are a lot of Clippy warnings

[brenomfviana]

I fixed some Clippy warnings in my pull request. But there are still the following warnings and errors:

warning: called `skip(x).next()` on an iterator
   --> curl-sys/build.rs:527:24
    |
527 |             let path = line.split('=').skip(1).next()?;
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(clippy::iter_skip_next)]` on by default
    = help: this is more succinctly expressed by calling `nth(x)`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#iter_skip_next

warning: 1 warning emitted

    Checking curl v0.4.33 (curl-rust)
warning: you should consider adding a `Default` implementation for `easy::form::Form`
  --> src/easy/form.rs:36:5
   |
36 | /     pub fn new() -> Form {
37 | |         Form {
38 | |             head: ptr::null_mut(),
39 | |             tail: ptr::null_mut(),
...  |
43 | |         }
44 | |     }
   | |_____^
   |
   = note: `#[warn(clippy::new_without_default)]` on by default
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default
help: try this
   |
34 | impl Default for easy::form::Form {
35 |     fn default() -> Self {
36 |         Self::new()
37 |     }
38 | }
   |

warning: very complex type used. Consider factoring parts into `type` definitions
   --> src/easy/handle.rs:108:12
    |
108 |     write: Option<Box<dyn FnMut(&[u8]) -> Result<usize, WriteError> + 'a>>,
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(clippy::type_complexity)]` on by default
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity

warning: very complex type used. Consider factoring parts into `type` definitions
   --> src/easy/handle.rs:109:11
    |
109 |     read: Option<Box<dyn FnMut(&mut [u8]) -> Result<usize, ReadError> + 'a>>,
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity

warning: very complex type used. Consider factoring parts into `type` definitions
   --> src/easy/handle.rs:111:12
    |
111 |     debug: Option<Box<dyn FnMut(InfoType, &[u8]) + 'a>>,
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity

warning: very complex type used. Consider factoring parts into `type` definitions
   --> src/easy/handle.rs:113:15
    |
113 |     progress: Option<Box<dyn FnMut(f64, f64, f64, f64) -> bool + 'a>>,
    |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity

warning: very complex type used. Consider factoring parts into `type` definitions
   --> src/easy/handle.rs:114:14
    |
114 |     ssl_ctx: Option<Box<dyn FnMut(*mut c_void) -> Result<(), Error> + 'a>>,
    |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity

warning: you should consider adding a `Default` implementation for `easy::handle::Easy`
   --> src/easy/handle.rs:125:5
    |
125 | /     pub fn new() -> Easy {
126 | |         Easy {
127 | |             inner: Easy2::new(EasyData {
128 | |                 running: Cell::new(false),
...   |
132 | |         }
133 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default
help: try this
    |
117 | impl Default for easy::handle::Easy {
118 |     fn default() -> Self {
119 |         Self::new()
120 |     }
121 | }
    |

error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing.
   --> src/easy/handler.rs:114:9
    |
114 |         drop(data);
    |         ^^^^^^^^^^
    |
    = note: `#[deny(clippy::drop_ref)]` on by default
note: argument has type `&mut [u8]`
   --> src/easy/handler.rs:114:14
    |
114 |         drop(data);
    |              ^^^^
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#drop_ref

error: calls to `std::mem::drop` with a value that implements `Copy`. Dropping a copy leaves the original intact.
   --> src/easy/handler.rs:138:9
    |
138 |         drop(whence);
    |         ^^^^^^^^^^^^
    |
    = note: `#[deny(clippy::drop_copy)]` on by default
note: argument has type std::io::SeekFrom
   --> src/easy/handler.rs:138:14
    |
138 |         drop(whence);
    |              ^^^^^^
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#drop_copy

error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing.
   --> src/easy/handler.rs:188:9
    |
188 |         drop(data);
    |         ^^^^^^^^^^
    |
note: argument has type `&[u8]`
   --> src/easy/handler.rs:188:14
    |
188 |         drop(data);
    |              ^^^^
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#drop_ref

error: calls to `std::mem::drop` with a value that implements `Copy`. Dropping a copy leaves the original intact.
   --> src/easy/handler.rs:224:9
    |
224 |         drop((dltotal, dlnow, ultotal, ulnow));
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
note: argument has type (f64, f64, f64, f64)
   --> src/easy/handler.rs:224:14
    |
224 |         drop((dltotal, dlnow, ultotal, ulnow));
    |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#drop_copy

warning: `0 as *const _` detected
    --> src/easy/handler.rs:1274:55
     |
1274 |         self.setopt_ptr(curl_sys::CURLOPT_POSTFIELDS, 0 as *const _)?;
     |                                                       ^^^^^^^^^^^^^ help: try: `std::ptr::null()`
     |
     = note: `#[warn(clippy::zero_ptr)]` on by default
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#zero_ptr

warning: Calling `subsec_millis()` is more concise than this calculation
    --> src/easy/handler.rs:1669:45
     |
1669 |         let ms = timeout.as_secs() * 1000 + (timeout.subsec_nanos() / 1_000_000) as u64;
     |                                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `timeout.subsec_millis()`
     |
     = note: `#[warn(clippy::duration_subsec)]` on by default
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#duration_subsec

warning: Calling `subsec_millis()` is more concise than this calculation
    --> src/easy/handler.rs:1780:45
     |
1780 |         let ms = timeout.as_secs() * 1000 + (timeout.subsec_nanos() / 1_000_000) as u64;
     |                                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `timeout.subsec_millis()`
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#duration_subsec

warning: this if-then-else expression returns a bool literal
    --> src/easy/handler.rs:2280:17
     |
2280 | /                 if r == 0 {
2281 | |                     false
2282 | |                 } else {
2283 | |                     true
2284 | |                 }
     | |_________________^ help: you can reduce it to: `!(r == 0)`
     |
     = note: `#[warn(clippy::needless_bool)]` on by default
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_bool

warning: length comparison to zero
    --> src/easy/handler.rs:2735:12
     |
2735 |         if s.len() == 0 {
     |            ^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `s.is_empty()`
     |
     = note: `#[warn(clippy::len_zero)]` on by default
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero

warning: length comparison to zero
    --> src/easy/handler.rs:2754:12
     |
2754 |         if s.len() == 0 {
     |            ^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `s.is_empty()`
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero

warning: `0 as *const _` detected
    --> src/easy/handler.rs:2909:25
     |
2909 |             let mut p = 0 as *const c_char;
     |                         ^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::null::<c_char>()`
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#zero_ptr

warning: use of `unwrap_or` followed by a function call
    --> src/easy/handler.rs:2964:52
     |
2964 |         let pos = buf.iter().position(|i| *i == 0).unwrap_or(buf.len());
     |                                                    ^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| buf.len())`
     |
     = note: `#[warn(clippy::or_fun_call)]` on by default
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call

warning: you should consider adding a `Default` implementation for `easy::handler::Auth`
    --> src/easy/handler.rs:3175:5
     |
3175 | /     pub fn new() -> Auth {
3176 | |         Auth { bits: 0 }
3177 | |     }
     | |_____^
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default
help: try this
     |
3170 | impl Default for easy::handler::Auth {
3171 |     fn default() -> Self {
3172 |         Self::new()
3173 |     }
3174 | }
     |

warning: you should consider adding a `Default` implementation for `easy::handler::SslOpt`
    --> src/easy/handler.rs:3283:5
     |
3283 | /     pub fn new() -> SslOpt {
3284 | |         SslOpt { bits: 0 }
3285 | |     }
     | |_____^
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default
help: try this
     |
3281 | impl Default for easy::handler::SslOpt {
3282 |     fn default() -> Self {
3283 |         Self::new()
3284 |     }
3285 | }
     |

warning: you should consider adding a `Default` implementation for `easy::list::List`
  --> src/easy/list.rs:32:5
   |
32 | /     pub fn new() -> List {
33 | |         List {
34 | |             raw: ptr::null_mut(),
35 | |         }
36 | |     }
   | |_____^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default
help: try this
   |
30 | impl Default for easy::list::List {
31 |     fn default() -> Self {
32 |         Self::new()
33 |     }
34 | }
   |

warning: you should consider adding a `Default` implementation for `multi::Multi`
   --> src/multi.rs:98:5
    |
98  | /     pub fn new() -> Multi {
99  | |         unsafe {
100 | |             ::init();
101 | |             let ptr = curl_sys::curl_multi_init();
...   |
110 | |         }
111 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default
help: try this
    |
95  | impl Default for multi::Multi {
96  |     fn default() -> Self {
97  |         Self::new()
98  |     }
99  | }
    |

warning: you should consider adding a `Default` implementation for `multi::Events`
    --> src/multi.rs:1010:5
     |
1010 | /     pub fn new() -> Events {
1011 | |         Events { bits: 0 }
1012 | |     }
     | |_____^
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default
help: try this
     |
1008 | impl Default for multi::Events {
1009 |     fn default() -> Self {
1010 |         Self::new()
1011 |     }
1012 | }
     |

warning: you should consider adding a `Default` implementation for `multi::WaitFd`
    --> src/multi.rs:1085:5
     |
1085 | /     pub fn new() -> WaitFd {
1086 | |         WaitFd {
1087 | |             inner: curl_sys::curl_waitfd {
1088 | |                 fd: 0,
...    |
1092 | |         }
1093 | |     }
     | |_____^
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default
help: try this
     |
1083 | impl Default for multi::WaitFd {
1084 |     fn default() -> Self {
1085 |         Self::new()
1086 |     }
1087 | }
     |

error: aborting due to 4 previous errors; 21 warnings emitted

[alexcrichton]

Thanks for the report! I would prefer to not keep an issue tracking this, however, since clippy is not something I'm tracking on this repository.