Merge pull request #1625 from CosmWasm/timestamp-must_use

Add #[must_use] annotations to Timestamp math functions

Author: webmaster128

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to
 
 - cosmwasm-std: Add an IBC querier implementation to `testing::MockQuerier`
   ([#1620], [#1624]).
+- cosmwasm-std: Add `#[must_use]` annotations to `Timestamp` math functions.
 
 [#1620]: https://github.com/CosmWasm/cosmwasm/pull/1620
 [#1624]: https://github.com/CosmWasm/cosmwasm/pull/1624

packages/std/src/timestamp.rs

@@ -38,19 +38,23 @@ impl Timestamp {
         Timestamp(Uint64::new(seconds_since_epoch * 1_000_000_000))
     }
 
+    #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn plus_seconds(&self, addition: u64) -> Timestamp {
         self.plus_nanos(addition * 1_000_000_000)
     }
 
+    #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn plus_nanos(&self, addition: u64) -> Timestamp {
         let nanos = Uint64::new(self.0.u64() + addition);
         Timestamp(nanos)
     }
 
+    #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn minus_seconds(&self, subtrahend: u64) -> Timestamp {
         self.minus_nanos(subtrahend * 1_000_000_000)
     }
 
+    #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn minus_nanos(&self, subtrahend: u64) -> Timestamp {
         let nanos = Uint64::new(self.0.u64() - subtrahend);
         Timestamp(nanos)