Make all PerThing types implement all trait methods on the type (#5422)

This removes the requirement to import `PerThing` to use a type that
implements the trait.

substrate/primitives/arithmetic/src/per_things.rs

@@ -19,9 +19,7 @@ use serde::{Serialize, Deserialize};
 
 use sp_std::{ops, fmt, prelude::*, convert::TryInto};
 use codec::{Encode, Decode, CompactAs};
-use crate::{
-	traits::{SaturatedConversion, UniqueSaturatedInto, Saturating, BaseArithmetic, Bounded},
-};
+use crate::traits::{SaturatedConversion, UniqueSaturatedInto, Saturating, BaseArithmetic, Bounded};
 use sp_debug_derive::RuntimeDebug;
 
 /// Something that implements a fixed point ration with an arbitrary granularity `X`, as _parts per
@@ -103,8 +101,8 @@ pub trait PerThing:
 	/// # }
 	/// ```
 	fn mul_collapse<N>(self, b: N) -> N
-	where N: Clone + From<Self::Inner> + UniqueSaturatedInto<Self::Inner> + ops::Rem<N, Output=N>
-		+ ops::Div<N, Output=N> + ops::Mul<N, Output=N> + ops::Add<N, Output=N>;
+		where N: Clone + From<Self::Inner> + UniqueSaturatedInto<Self::Inner> + ops::Rem<N, Output=N>
+			+ ops::Div<N, Output=N> + ops::Mul<N, Output=N> + ops::Add<N, Output=N>;
 }
 
 macro_rules! implement_per_thing {
@@ -259,13 +257,52 @@ macro_rules! implement_per_thing {
 				Self([x, 100][(x > 100) as usize] * ($max / 100))
 			}
 
-			/// Everything.
-			///
-			/// To avoid having to import `PerThing` when one needs to be used in test mocks.
-			#[cfg(feature = "std")]
+			/// See [`PerThing::one`].
 			pub fn one() -> Self {
 				<Self as PerThing>::one()
 			}
+
+			/// See [`PerThing::zero`].
+			pub fn zero() -> Self {
+				<Self as PerThing>::zero()
+			}
+
+			/// See [`PerThing::is_zero`].
+			pub fn is_zero(&self) -> bool {
+				PerThing::is_zero(self)
+			}
+
+			/// See [`PerThing::deconstruct`].
+			pub fn deconstruct(self) -> $type {
+				PerThing::deconstruct(self)
+			}
+
+			/// See [`PerThing::square`].
+			pub fn square(self) -> Self {
+				PerThing::square(self)
+			}
+
+			/// See [`PerThing::from_fraction`].
+			#[cfg(feature = "std")]
+			pub fn from_fraction(x: f64) -> Self {
+				<Self as PerThing>::from_fraction(x)
+			}
+
+			/// See [`PerThing::from_rational_approximation`].
+			pub fn from_rational_approximation<N>(p: N, q: N) -> Self
+				where N: Clone + Ord + From<$type> + TryInto<$type> +
+					TryInto<$upper_type> + ops::Div<N, Output=N> + ops::Rem<N, Output=N> +
+					ops::Add<N, Output=N> {
+				<Self as PerThing>::from_rational_approximation(p, q)
+			}
+
+			/// See [`PerThing::mul_collapse`].
+			pub fn mul_collapse<N>(self, b: N) -> N
+				where N: Clone + From<$type> + UniqueSaturatedInto<$type> +
+					ops::Rem<N, Output=N> + ops::Div<N, Output=N> + ops::Mul<N, Output=N> +
+					ops::Add<N, Output=N> {
+				PerThing::mul_collapse(self, b)
+			}
 		}
 
 		impl Saturating for $name {