Merge pull request #1366 from CosmWasm/1186-implement-min-const

`Uint`/`Decimal`: Implement const MIN

CHANGELOG.md

@@ -19,6 +19,7 @@ and this project adheres to
 - cosmwasm-std: Implement `ceil`/`floor` for `Decimal`/`Decimal256`.
 - cosmwasm-std: Implement `saturating_add`/`sub`/`mul` for
   `Decimal`/`Decimal256`.
+- cosmwasm-std: Implement `MIN` const value for all `Uint` and `Decimal` types
 
 [#1334]: https://github.com/CosmWasm/cosmwasm/pull/1334
 

packages/std/src/math/decimal.rs

@@ -36,6 +36,8 @@ impl Decimal {
     pub const DECIMAL_PLACES: u32 = 18; // This needs to be an even number.
     /// The largest value that can be represented by this decimal type.
     pub const MAX: Self = Self(Uint128::MAX);
+    /// The smallest value that can be represented by this decimal type.
+    pub const MIN: Self = Self(Uint128::MIN);
 
     /// Creates a Decimal(value)
     /// This is equivalent to `Decimal::from_atomics(value, 18)` but usable in a const context.

packages/std/src/math/decimal256.rs

@@ -46,6 +46,8 @@ impl Decimal256 {
     pub const DECIMAL_PLACES: u32 = 18;
     /// The largest value that can be represented by this decimal type.
     pub const MAX: Self = Self(Uint256::MAX);
+    /// The smallest value that can be represented by this decimal type.
+    pub const MIN: Self = Self(Uint256::MIN);
 
     /// Creates a Decimal256 from Uint256
     /// This is equivalent to `Decimal256::from_atomics(value, 18)` but usable in a const context.

packages/std/src/math/uint128.rs

@@ -36,6 +36,7 @@ pub struct Uint128(#[schemars(with = "String")] u128);
 
 impl Uint128 {
     pub const MAX: Self = Self(u128::MAX);
+    pub const MIN: Self = Self(u128::MIN);
 
     /// Creates a Uint128(value).
     ///

packages/std/src/math/uint256.rs

@@ -52,6 +52,7 @@ pub struct Uint256(#[schemars(with = "String")] U256);
 
 impl Uint256 {
     pub const MAX: Uint256 = Uint256(U256::MAX);
+    pub const MIN: Uint256 = Uint256(U256::zero());
 
     /// Creates a Uint256(value) from a big endian representation. It's just an alias for
     /// [`Uint256::from_be_bytes`].

packages/std/src/math/uint512.rs

@@ -54,6 +54,7 @@ pub struct Uint512(#[schemars(with = "String")] U512);
 
 impl Uint512 {
     pub const MAX: Uint512 = Uint512(U512::MAX);
+    pub const MIN: Uint512 = Uint512(U512::zero());
 
     /// Creates a Uint512(value) from a big endian representation. It's just an alias for
     /// `from_big_endian`.

packages/std/src/math/uint64.rs

@@ -32,6 +32,7 @@ pub struct Uint64(#[schemars(with = "String")] u64);
 
 impl Uint64 {
     pub const MAX: Self = Self(u64::MAX);
+    pub const MIN: Self = Self(u64::MIN);
 
     /// Creates a Uint64(value).
     ///