sigils/src/bounded.rs

// SPDX-License-Identifier: Apache-2.0
// Sealed with Magistamp.

/// `Bounded` provides the inclusive minimum and maximum range limits
/// for a numeric type.
///
/// Rust types have actual upper and lower representation limits that don't
/// follow the mathematical definitions. For example a Natural number goes
/// from one to infinity but a u8 can only really represent a number between
/// zero and two hundred and fifty five. This let's use set the minimum and
/// maximum values a Rust type can represent so we can use them in code easily.
pub trait Bounded
{
   /// The minimum value for this type.
   ///
   /// # Examples
   /// ```rust
   /// use sigils::Bounded;
   ///
   /// let min = <u8 as Bounded>::MIN;
   ///
   /// assert_eq!(min, u8::MIN);
   /// ```
   const MIN: Self;

   /// The maximum value for this type.
   ///
   /// # Examples
   /// ```rust
   /// use sigils::Bounded;
   ///
   /// let max = <f64 as Bounded>::MAX;
   ///
   /// assert_eq!(max, f64::MAX);
   /// ```
   const MAX: Self;
}



/// A macro for making implementation of
/// the Bounded trait easier.
macro_rules! bounded_trait_impl
{
   ($($T:ty),*) =>
   {
      $(
         impl Bounded for $T
         {
            const MIN: $T = <$T>::MIN;
            const MAX: $T = <$T>::MAX;
         }
      )*
   }
}


// Implement the Bounded for all the primitive types.
bounded_trait_impl!(u8, u16, u32, u64, u128, usize);
bounded_trait_impl!(i8, i16, i32, i64, i128, isize);
bounded_trait_impl!(f32, f64);