Upgrade project to edition 2018 (#389)

* Run `cargo fix`

* Fix edition warnings

* Cargo.toml to edition 2018

* Remove all extern crate

* Link to mesalink explicitly

Author: weihanglo

Cargo.toml

@@ -10,6 +10,7 @@ description = "Rust bindings to libcurl for making HTTP requests"
 categories = ["api-bindings", "web-programming::http-client"]
 readme = "README.md"
 autotests = true
+edition = "2018"
 
 [badges]
 travis-ci = { repository = "alexcrichton/curl-rust" }

curl-sys/Cargo.toml

@@ -9,6 +9,7 @@ repository = "https://github.com/alexcrichton/curl-rust"
 description = "Native bindings to the libcurl library"
 documentation = "https://docs.rs/curl-sys"
 categories = ["external-ffi-bindings"]
+edition = "2018"
 
 [badges]
 travis-ci = { repository = "alexcrichton/curl-rust" }

curl-sys/build.rs

@@ -1,8 +1,3 @@
-extern crate cc;
-extern crate pkg_config;
-#[cfg(target_env = "msvc")]
-extern crate vcpkg;
-
 use std::env;
 use std::fs;
 use std::path::{Path, PathBuf};

curl-sys/lib.rs

@@ -1,17 +1,15 @@
 #![allow(bad_style)]
 #![doc(html_root_url = "https://docs.rs/curl-sys/0.3")]
 
-extern crate libc;
+// These `extern crate` are required for conditional linkages of curl.
 #[cfg(link_libnghttp2)]
 extern crate libnghttp2_sys;
 #[cfg(link_libz)]
 extern crate libz_sys;
 #[cfg(feature = "mesalink")]
-extern crate mesalink; // ensure lib is linked to
+extern crate mesalink;
 #[cfg(link_openssl)]
 extern crate openssl_sys;
-#[cfg(windows)]
-extern crate winapi;
 
 use libc::c_ulong;
 use libc::{c_char, c_double, c_int, c_long, c_short, c_uint, c_void, size_t, time_t};

examples/ssl_cert_blob.rs

@@ -1,6 +1,3 @@
-extern crate anyhow;
-extern crate curl;
-
 use std::env;
 use std::fs::File;
 use std::io::{stdout, Read, Write};

examples/ssl_proxy.rs

@@ -1,5 +1,3 @@
-extern crate anyhow;
-
 use anyhow::Result;
 
 fn main() -> Result<()> {

src/easy/form.rs

@@ -3,9 +3,9 @@ use std::fmt;
 use std::path::Path;
 use std::ptr;
 
+use crate::easy::{list, List};
+use crate::FormError;
 use curl_sys;
-use easy::{list, List};
-use FormError;
 
 /// Multipart/formdata for an HTTP POST request.
 ///

src/easy/handle.rs

@@ -9,12 +9,12 @@ use std::time::Duration;
 use curl_sys;
 use libc::c_void;
 
-use easy::handler::{self, InfoType, ReadError, SeekResult, WriteError};
-use easy::handler::{Auth, NetRc, ProxyType, SslOpt};
-use easy::handler::{HttpVersion, IpResolve, SslVersion, TimeCondition};
-use easy::{Easy2, Handler};
-use easy::{Form, List};
-use Error;
+use crate::easy::handler::{self, InfoType, ReadError, SeekResult, WriteError};
+use crate::easy::handler::{Auth, NetRc, ProxyType, SslOpt};
+use crate::easy::handler::{HttpVersion, IpResolve, SslVersion, TimeCondition};
+use crate::easy::{Easy2, Handler};
+use crate::easy::{Form, List};
+use crate::Error;
 
 /// Raw bindings to a libcurl "easy session".
 ///

src/easy/handler.rs

@@ -12,12 +12,12 @@ use curl_sys;
 use libc::{self, c_char, c_double, c_int, c_long, c_ulong, c_void, size_t};
 use socket2::Socket;
 
-use easy::form;
-use easy::list;
-use easy::windows;
-use easy::{Form, List};
-use panic;
-use Error;
+use crate::easy::form;
+use crate::easy::list;
+use crate::easy::windows;
+use crate::easy::{Form, List};
+use crate::panic;
+use crate::Error;
 
 /// A trait for the various callbacks used by libcurl to invoke user code.
 ///
@@ -581,7 +581,7 @@ impl<H: Handler> Easy2<H> {
     /// `perform` and need to be reset manually (or via the `reset` method) if
     /// this is not desired.
     pub fn new(handler: H) -> Easy2<H> {
-        ::init();
+        crate::init();
         unsafe {
             let handle = curl_sys::curl_easy_init();
             assert!(!handle.is_null());

src/easy/list.rs

@@ -2,8 +2,8 @@ use std::ffi::{CStr, CString};
 use std::fmt;
 use std::ptr;
 
+use crate::Error;
 use curl_sys;
-use Error;
 
 /// A linked list of a strings
 pub struct List {