transition paths to 2018 edition

Replaces all `extern crate ...` and especially #[macro_use] statements
with direct `use`s of relevant items.

Introduces cstr! crate & macro to examples, because we don't want our dear
users/readers to suffer with raw CStr nightmare:
    std::ffi::CStr::from_bytes_with_nul(b"...\0").unwrap()

Author: ratijas

README.md

@@ -18,9 +18,7 @@ Presentation Blog Post: https://woboq.com/blog/qmetaobject-from-rust.html
 ## Overview
 
 ```rust
-#[macro_use] extern crate cstr;
-extern crate qmetaobject;
-
+use cstr::cstr;
 use qmetaobject::*;
 
 // The `QObject` custom derive macro allows to expose a class to Qt and QML

examples/graph/build.rs

@@ -15,7 +15,6 @@ NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FO
 OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
-extern crate cpp_build;
 
 fn main() {
     let qt_include_path = std::env::var("DEP_QT_INCLUDE_PATH").unwrap();

examples/qmlextensionplugins/Cargo.toml

@@ -11,3 +11,4 @@ crate-type = ["cdylib"]
 [dependencies]
 qmetaobject = { path = "../../qmetaobject"}
 chrono = "^0.4"
+cstr = "0.2"

examples/qmlextensionplugins/src/lib.rs

@@ -1,10 +1,12 @@
-extern crate qmetaobject;
-use qmetaobject::*;
-extern crate chrono;
-use chrono::Timelike;
+use std::ffi::CStr;
 use std::sync::{Arc, Condvar, Mutex};
 use std::thread::JoinHandle;
 
+use chrono::Timelike;
+use cstr::cstr;
+
+use qmetaobject::*;
+
 #[derive(Default)]
 struct AbortCondVar {
     is_aborted: Mutex<bool>,
@@ -75,13 +77,8 @@ struct QExampleQmlPlugin {
 }
 
 impl QQmlExtensionPlugin for QExampleQmlPlugin {
-    fn register_types(&mut self, uri: &std::ffi::CStr) {
+    fn register_types(&mut self, uri: &CStr) {
         //assert_eq!(uri, std::ffi::CStr::from_bytes_with_nul(b"TimeExample\0"));
-        qml_register_type::<TimeModel>(
-            uri,
-            1,
-            0,
-            std::ffi::CStr::from_bytes_with_nul(b"Time\0").unwrap(),
-        );
+        qml_register_type::<TimeModel>(uri, 1, 0, cstr!("Time"));
     }
 }

examples/todos/Cargo.toml

@@ -6,3 +6,4 @@ authors = ["Olivier Goffart <ogoffart@woboq.com>"]
 
 [dependencies]
 qmetaobject = { path = "../../qmetaobject"}
+cstr = "0.2"

examples/todos/src/implementation.rs

@@ -18,9 +18,10 @@
  *   You should have received a copy of the GNU General Public License
  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-use qmetaobject::*;
 use std::collections::HashMap;
 
+use qmetaobject::*;
+
 #[derive(Default, Clone)]
 struct TodosItem {
     completed: bool,

examples/todos/src/main.rs

@@ -1,7 +1,6 @@
-extern crate qmetaobject;
-use qmetaobject::*;
+use cstr::cstr;
 
-use std::ffi::CStr;
+use qmetaobject::*;
 
 mod implementation;
 
@@ -13,12 +12,7 @@ qrc!(my_resource,
 
 fn main() {
     my_resource();
-    qml_register_type::<implementation::Todos>(
-        CStr::from_bytes_with_nul(b"RustCode\0").unwrap(),
-        1,
-        0,
-        CStr::from_bytes_with_nul(b"Todos\0").unwrap(),
-    );
+    qml_register_type::<implementation::Todos>(cstr!("RustCode"), 1, 0, cstr!("Todos"));
     let mut engine = QmlEngine::new();
     engine.load_file("qrc:/todos/qml/main.qml".into());
     engine.exec();

examples/webengine/src/main.rs

@@ -1,4 +1,3 @@
-extern crate qmetaobject;
 use qmetaobject::*;
 
 qrc!(my_resource,

qmetaobject/src/connections.rs

@@ -84,6 +84,8 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #![deny(missing_docs)]
 use std::os::raw::c_void;
 
+use cpp::{cpp, cpp_class};
+
 use super::*;
 
 /// Inner functor type of a `QRustClosureSlotObject` class.
@@ -282,7 +284,7 @@ impl<Args> Signal<Args> {
     /// # Example
     ///
     /// ```
-    /// #[macro_use] extern crate cpp;
+    /// use cpp::cpp;
     /// use qmetaobject::*;
     ///
     /// fn object_name_changed() -> Signal<fn(QString)> {

qmetaobject/src/future.rs

@@ -4,6 +4,8 @@ use std::os::raw::c_void;
 use std::pin::Pin;
 use std::task::{Context, Poll, RawWaker, RawWakerVTable, Waker};
 
+use cpp::cpp;
+
 use crate::connections::SignalArgArrayToTuple;
 
 static QT_WAKER_VTABLE: RawWakerVTable = RawWakerVTable::new(