Add const implementations for is_zero/atomics/decimal_places methods

CHANGELOG.md

@@ -19,6 +19,8 @@ and this project adheres to
 - cosmwasm-std: Implement `pow`/`checked_pow` for `Uint64`/`Uint128`/`Uint512`.
 - cosmwasm-std: Implement `SubAssign`/`AddAssign` for `Decimal`/`Decimal256`.
 - cosmwasm-std: Implement `MulAssign` for `Decimal`/`Decimal256`.
+- cosmwasm-std: Implement `is_zero`/`atomics`/`decimal_places` as const for Uint
+  and Decimal types.
 - cosmwasm-crypto: Upgrade ed25519-zebra to version 3.
 
 ### Changed

packages/std/src/math/decimal.rs

@@ -119,7 +119,7 @@ impl Decimal {
         )
     }
 
-    pub fn is_zero(&self) -> bool {
+    pub const fn is_zero(&self) -> bool {
         self.0.is_zero()
     }
 
@@ -141,15 +141,15 @@ impl Decimal {
     /// assert_eq!(b.decimal_places(), 18);
     /// assert_eq!(b.atomics(), Uint128::new(1));
     /// ```
-    pub fn atomics(&self) -> Uint128 {
+    pub const fn atomics(&self) -> Uint128 {
         self.0
     }
 
     /// The number of decimal places. This is a constant value for now
     /// but this could potentially change as the type evolves.
     ///
     /// See also [`Decimal::atomics()`].
-    pub fn decimal_places(&self) -> u32 {
+    pub const fn decimal_places(&self) -> u32 {
         Self::DECIMAL_PLACES as u32
     }
 

packages/std/src/math/decimal256.rs

@@ -131,7 +131,7 @@ impl Decimal256 {
         )
     }
 
-    pub fn is_zero(&self) -> bool {
+    pub const fn is_zero(&self) -> bool {
         self.0.is_zero()
     }
 
@@ -153,15 +153,15 @@ impl Decimal256 {
     /// assert_eq!(b.decimal_places(), 18);
     /// assert_eq!(b.atomics(), Uint256::from(1u128));
     /// ```
-    pub fn atomics(&self) -> Uint256 {
+    pub const fn atomics(&self) -> Uint256 {
         self.0
     }
 
     /// The number of decimal places. This is a constant value for now
     /// but this could potentially change as the type evolves.
     ///
     /// See also [`Decimal256::atomics()`].
-    pub fn decimal_places(&self) -> u32 {
+    pub const fn decimal_places(&self) -> u32 {
         Self::DECIMAL_PLACES as u32
     }
 

packages/std/src/math/uint128.rs

@@ -63,7 +63,7 @@ impl Uint128 {
         self.0.to_le_bytes()
     }
 
-    pub fn is_zero(&self) -> bool {
+    pub const fn is_zero(&self) -> bool {
         self.0 == 0
     }
 

packages/std/src/math/uint256.rs

@@ -206,8 +206,9 @@ impl Uint256 {
         ]
     }
 
-    pub fn is_zero(&self) -> bool {
-        self.0.is_zero()
+    pub const fn is_zero(&self) -> bool {
+        let words = (self.0).0;
+        words[0] == 0 && words[1] == 0 && words[2] == 0 && words[3] == 0
     }
 
     pub fn pow(self, exp: u32) -> Self {

packages/std/src/math/uint512.rs

@@ -58,7 +58,7 @@ impl Uint512 {
 
     /// Creates a Uint512(value) from a big endian representation. It's just an alias for
     /// `from_big_endian`.
-    pub fn new(value: [u8; 64]) -> Self {
+    pub const fn new(value: [u8; 64]) -> Self {
         Self::from_be_bytes(value)
     }
 
@@ -305,8 +305,16 @@ impl Uint512 {
         ]
     }
 
-    pub fn is_zero(&self) -> bool {
-        self.0.is_zero()
+    pub const fn is_zero(&self) -> bool {
+        let words = (self.0).0;
+        words[0] == 0
+            && words[1] == 0
+            && words[2] == 0
+            && words[3] == 0
+            && words[4] == 0
+            && words[5] == 0
+            && words[6] == 0
+            && words[7] == 0
     }
 
     pub fn pow(self, exp: u32) -> Self {

packages/std/src/math/uint64.rs

@@ -59,7 +59,7 @@ impl Uint64 {
         self.0.to_le_bytes()
     }
 
-    pub fn is_zero(&self) -> bool {
+    pub const fn is_zero(&self) -> bool {
         self.0 == 0
     }