fix beta clippy warnings

Author: bilelmoussaoui

gdk4/src/content_formats_builder.rs

@@ -5,6 +5,7 @@ use glib::translate::*;
 
 impl ContentFormatsBuilder {
     #[doc(alias = "gdk_content_formats_builder_add_formats")]
+    #[must_use]
     pub fn add_formats(self, formats: &ContentFormats) -> Self {
         unsafe {
             ffi::gdk_content_formats_builder_add_formats(
@@ -17,6 +18,7 @@ impl ContentFormatsBuilder {
     }
 
     #[doc(alias = "gdk_content_formats_builder_add_gtype")]
+    #[must_use]
     pub fn add_type(self, type_: glib::types::Type) -> Self {
         unsafe {
             ffi::gdk_content_formats_builder_add_gtype(self.to_glib_none().0, type_.into_glib());
@@ -26,6 +28,7 @@ impl ContentFormatsBuilder {
     }
 
     #[doc(alias = "gdk_content_formats_builder_add_mime_type")]
+    #[must_use]
     pub fn add_mime_type(self, mime_type: &str) -> Self {
         unsafe {
             ffi::gdk_content_formats_builder_add_mime_type(

gdk4/src/keys.rs

@@ -64,12 +64,14 @@ impl Key {
     }
 
     #[doc(alias = "gdk_keyval_to_upper")]
+    #[must_use]
     pub fn to_upper(&self) -> Self {
         skip_assert_initialized!();
         unsafe { from_glib(ffi::gdk_keyval_to_upper(self.into_glib())) }
     }
 
     #[doc(alias = "gdk_keyval_to_lower")]
+    #[must_use]
     pub fn to_lower(&self) -> Self {
         skip_assert_initialized!();
         unsafe { from_glib(ffi::gdk_keyval_to_lower(self.into_glib())) }

gtk4/src/subclass/entry_buffer.rs

@@ -299,7 +299,7 @@ fn text_n_chars(text: &str, n_chars: u32) -> &str {
             .expect(
                 "The passed text to EntryBuffer contains fewer characters than what's passed as a length",
             );
-        let pos_end = iter.next().unwrap_or_else(|| text.len());
+        let pos_end = iter.next().unwrap_or(text.len());
         &text[..pos_end]
     } else if n_chars == 0 {
         // Avoid doing skipping to -1 char