Add some must_use to jemalloc-ctl key APIs

jemalloc-ctl/src/keys.rs

@@ -88,6 +88,7 @@ impl Name {
 
     /// Returns `true` if `self` is a key in the _MALLCTL NAMESPCE_ referring to
     /// a null-terminated string.
+    #[must_use]
     pub fn value_type_str(&self) -> bool {
         // remove the null-terminator:
         let name = self.0.split_at(self.0.len() - 1).0;
@@ -117,6 +118,7 @@ impl Name {
     }
 
     /// Returns the name as null-terminated byte-string.
+    #[must_use]
     pub fn as_bytes(&self) -> &'static [u8] {
         unsafe { &*(self as *const Self as *const [u8]) }
     }

jemalloc-ctl/src/macros.rs

@@ -27,6 +27,7 @@ macro_rules! types {
                 }
 
                 /// Key [`::keys::Name`].
+                #[must_use]
                 pub fn name() -> &'static ::keys::Name {
                     Self::NAME
                 }

jemalloc-ctl/src/thread.rs

@@ -127,6 +127,7 @@ where
 {
     /// Returns the current value at the pointer.
     #[inline]
+    #[must_use]
     pub fn get(self) -> T {
         unsafe { *self.0 }
     }