Clean up unused warnings if disabled

src/lib.rs

-use std::convert::AsRef;
-use std::io::prelude::*;
-use std::sync::atomic::AtomicPtr;
-use std::sync::atomic::Ordering;
+#[cfg(feature = "xlap")]
+use std::{
+    convert::AsRef,
+    io::prelude::*,
+    sync::atomic::{AtomicPtr, Ordering},
+};
 use std::time::Instant;
 
+#[cfg(feature = "xlap")]
 use strum::{AsRefStr, EnumCount, EnumIter, IntoEnumIterator};
 
 // Include the correct function for cycle counts depending on the architecture
-#[cfg(target_arch = "x86")]
+#[cfg(all(target_arch = "x86", feature = "xlap"))]
 use core::arch::x86::_rdtsc as current_cycle;
-#[cfg(target_arch = "x86_64")]
+#[cfg(all(target_arch = "x86_64", feature = "xlap"))]
 use core::arch::x86_64::_rdtsc as current_cycle;
 // On all other architectures there is no cycle counting, so just set it to zero
-#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
+#[cfg(all(not(any(target_arch = "x86", target_arch = "x86_64")), feature = "xlap"))]
 #[inline(always)]
 pub unsafe fn current_cycle() -> u64 {
     0
@@ -41,6 +44,7 @@ include!(concat!(env!("OUT_DIR"), "/xlap_generated.rs"));
 // ---------------------------------------------
 
 /// A moment in time, expressed in cycles and time
+#[cfg(feature = "xlap")]
 struct Timestamp {
     c: u64,
     t: Instant,
@@ -205,9 +209,9 @@ macro_rules! kind {
     ( $kind:expr ) => {
         {
             #[cfg(feature = "xlap")]
-            $kind
+            { $kind }
             #[cfg(not(feature = "xlap"))]
-            $crate::Kind::NoKind
+            { $crate::Kind::NoKind }
         }
     }
 }