Provide a macro for HString literals

We could also use a null-terminating variant of wstr! internally in DEFINE_CLSID

Author: Boddlnagg

Cargo.toml

@@ -14,6 +14,7 @@ exclude = ["Generator/**"]
 
 [dependencies]
 winapi = { version = "0.3", features = ["winnt", "combaseapi", "oleauto", "roapi", "roerrorapi", "hstring", "winstring", "winerror", "restrictederrorinfo"] }
+wstr = "0.2"
 
 [features]
 nightly = []

examples/test.rs

@@ -15,8 +15,8 @@ fn main() {
 }
 
 fn run() {
-    let base = FastHString::new("https://github.com");
-    let relative = FastHString::new("contextfree/winrt-rust");
+    let base = hstr!("https://github.com");
+    let relative = hstr!("contextfree/winrt-rust");
     let uri = Uri::create_with_relative_uri(&base, &relative).unwrap();
     let to_string = unsafe { uri.query_interface::<IStringable>().unwrap().to_string().unwrap() };
     println!("{} -> {}", uri.get_runtime_class_name(), to_string);
@@ -126,17 +126,17 @@ fn run() {
     println!("{:?} = {:?}", array, &returned_array[..]);
     assert_eq!(array, &returned_array[..]);
 
-    let str1 = FastHString::new("foo");
-    let str2 = FastHString::new("bar");
-    let array = &mut [&*str1, &*str2, &*str1, &*str2];
+    let str1 = hstr!("foo");
+    let str2 = hstr!("bar");
+    let array = &mut [&*str1, &*str2, &*str1, &*str2]; // convert to array of `&HStringArg`
     let boxed_array = PropertyValue::create_string_array(array);
     let boxed_array = boxed_array.unwrap().query_interface::<IPropertyValue>().unwrap();
     assert_eq!(unsafe { boxed_array.get_type().unwrap() }, PropertyType::StringArray);
     let boxed_array = boxed_array.query_interface::<IReferenceArray<HString>>().unwrap();
     let returned_array = unsafe { boxed_array.get_value().unwrap() };
     assert_eq!(array.len(), returned_array.len());
     for i in 0..array.len() {
-        assert!(returned_array[i] == (if i % 2 == 0 { &str1 } else { &str2 }));
+        assert!(returned_array[i] == (if i % 2 == 0 { str1 } else { str2 }));
     }
     // TODO: test array interface objects (also see if ComArray drops contents correctly)
 

examples/toast_notify.rs

@@ -3,6 +3,7 @@
 // Use the following command to run this example:
 // > cargo run --example toast_notify --features "windows-data windows-ui"
 
+#[macro_use]
 extern crate winrt;
 
 use winrt::*;
@@ -20,10 +21,10 @@ fn run() { unsafe {
     let toast_xml = ToastNotificationManager::get_template_content(ToastTemplateType::ToastText02).unwrap();
 
     // Fill in the text elements
-    let toast_text_elements = toast_xml.get_elements_by_tag_name(&FastHString::new("text")).unwrap();
+    let toast_text_elements = toast_xml.get_elements_by_tag_name(&*hstr!("text")).unwrap();
 
-    toast_text_elements.item(0).unwrap().append_child(&*toast_xml.create_text_node(&FastHString::new("Hello from Rust!")).unwrap().query_interface::<IXmlNode>().unwrap()).unwrap();
-    toast_text_elements.item(1).unwrap().append_child(&*toast_xml.create_text_node(&FastHString::new("This is some more text.")).unwrap().query_interface::<IXmlNode>().unwrap()).unwrap();
+    toast_text_elements.item(0).unwrap().append_child(&*toast_xml.create_text_node(&*hstr!("Hello from Rust!")).unwrap().query_interface::<IXmlNode>().unwrap()).unwrap();
+    toast_text_elements.item(1).unwrap().append_child(&*toast_xml.create_text_node(&*hstr!("This is some more text.")).unwrap().query_interface::<IXmlNode>().unwrap()).unwrap();
 
     // could use the following to get the XML code for the notification
     //println!("{}", toast_xml.query_interface::<IXmlNodeSerializer>().unwrap().get_xml().unwrap());
@@ -32,5 +33,5 @@ fn run() { unsafe {
     let toast = ToastNotification::create_toast_notification(&*toast_xml).unwrap();
 
     // Show the toast. Use PowerShell's App ID to circumvent the need to register one (this is only an example!).
-    ToastNotificationManager::create_toast_notifier_with_id(&FastHString::new("{1AC14E77-02E7-4E5D-B744-2EB1AE5198B7}\\WindowsPowerShell\\v1.0\\powershell.exe")).unwrap().show(&*toast).unwrap();
+    ToastNotificationManager::create_toast_notifier_with_id(&*hstr!("{1AC14E77-02E7-4E5D-B744-2EB1AE5198B7}\\WindowsPowerShell\\v1.0\\powershell.exe")).unwrap().show(&*toast).unwrap();
 }}

src/comptr.rs

@@ -83,7 +83,7 @@ impl<T> ComPtr<T> {
     /// use winrt::windows::foundation::Uri;
     ///
     /// # let rt = winrt::RuntimeContext::init();
-    /// let uri = FastHString::new("https://www.rust-lang.org");
+    /// let uri = hstr!("https://www.rust-lang.org");
     /// let uri = Uri::create_uri(&uri).unwrap();
     /// assert_eq!("Windows.Foundation.Uri", uri.get_runtime_class_name().to_string());
     /// ```

src/hstring.rs

@@ -363,7 +363,7 @@ pub struct HString(HSTRING);
 impl HString {
     /// Creates a new `HString` whose memory is managed by the Windows Runtime.
     /// This allocates twice (once for the conversion to UTF-16, and again within `WindowsCreateString`),
-    /// therefore this should not be used. Use `FastHString::new()` instead.
+    /// therefore this should not be used. Use the `hstr!` macro or `FastHString::new()` instead.
     pub fn new<'a>(s: &'a str) -> HString {
         // Every UTF-8 byte results in either 1 or 2 UTF-16 bytes and we need one
         // more for the null terminator. This size expectation is correct in most cases,
@@ -583,6 +583,22 @@ mod tests {
         assert!(s == hstr.to_string());
     }
 
+    #[test]
+    fn roundtrip_macro() {
+        let hstr = hstr!("12345");
+        assert!(hstr.len() as usize == "12345".len());
+        assert!("12345" == hstr.to_string());
+    }
+
+    #[test]
+    fn roundtrip_utf16_internal_nul() {
+        let s = "This is some\0test string\0with internal nuls";
+        let utf16: Vec<_> = s.encode_utf16().chain(Some(0)).collect();
+        let hstr = HStringReference::from_utf16(&utf16);
+        assert!(hstr.len() as usize == s.len());
+        assert!(s == hstr.to_string());
+    }
+
     #[test]
     fn make_reference() {
         let s1 = HString::new("AAA");
@@ -670,47 +686,54 @@ mod tests {
     fn bench_create(b: &mut Bencher) {
         let s = "123456789";
         b.iter(|| {
-            let _ = HString::new(s);
+            HString::new(s)
         });;
     }
 
     #[bench]
     fn bench_create_fast(b: &mut Bencher) {
         let s = "123456789";
         b.iter(|| {
-            let _ = FastHString::new(s);
+            FastHString::new(s)
+        });
+    }
+
+    #[bench]
+    fn bench_create_macro_literal(b: &mut Bencher) {
+        b.iter(|| {
+            hstr!("123456789")
         });
     }
 
     #[bench]
     fn bench_make_reference(b: &mut Bencher) {
         let s = HString::new("123456789");
         b.iter(|| {
-            let _ = s.make_reference();
+            s.make_reference()
         });
     }
 
     #[bench]
     fn bench_make_reference_fast(b: &mut Bencher) {
         let s = FastHString::new("123456789");
         b.iter(|| {
-            let _ = s.make_reference();
+            s.make_reference()
         });
     }
 
     #[bench]
     fn bench_from_utf16(b: &mut Bencher) {
         let utf16: Vec<_> = "This is some test string".encode_utf16().chain(Some(0)).collect();
         b.iter(|| {
-            let _ = HStringReference::from_utf16(&utf16);
+            HStringReference::from_utf16(&utf16)
         });
     }
 
     #[bench]
     fn bench_to_string(b: &mut Bencher) {
         let hstr = FastHString::new("123456789");
         b.iter(|| {
-            let _ = hstr.to_string();
+            hstr.to_string()
         });
     }
 }

src/lib.rs

@@ -28,11 +28,27 @@
 
 #![allow(dead_code,non_upper_case_globals,non_snake_case)]
 
+#[macro_use]
+extern crate wstr;
+pub use wstr::*;
+
 extern crate winapi as w;
 
 mod guid;
 pub use guid::Guid;
 
+/// Creates an `HStringReference` from a string literal.
+/// This is the fastest and easiest way to pass `HString` literals
+/// to WinRT functions.
+#[macro_export]
+macro_rules! hstr {
+    ($str: tt) => {{
+        let s = wstrz!($str);
+        #[allow(unused_unsafe)]
+        unsafe { HStringReference::from_utf16_unchecked(s) }
+    }}
+}
+
 ///Represents the trust level of an activatable class (re-export from WinAPI crate)
 pub type TrustLevel = ::w::winrt::inspectable::TrustLevel;