Add back std feature flag, and fix small error in test configure gate

Author: all-is-to-be-dared

Cargo.toml

@@ -50,6 +50,9 @@ disable-cache-padding = [
     "maitake-sync?/no-cache-pad",
 ]
 alloc = []
+std = [
+    "alloc"
+]
 maitake-sync-0_2 = [
     "dep:maitake-sync",
 ]

src/lib.rs

@@ -29,7 +29,7 @@ pub mod export {
     pub use const_init::ConstInit;
 }
 
-#[cfg(test)]
+#[cfg(all(test, feature = "alloc"))]
 mod test {
     use core::{ops::Deref, time::Duration};