add ZERO, DELTA, ONE constants

README.md

@@ -81,6 +81,12 @@ The conversions supported cover the following cases.
 
 ### Version 1.8.0 news (unreleased)
 
+  * The following constants were added to all fixed-point numbers, to
+    the [`Fixed`][tf-1-8] trait, and to the [`Wrapping`][w-1-8] and
+    [`Unwrapped`][u-1-8] wrappers:
+      * [`ZERO`][f-z-1-8], [`DELTA`][f-d-1-8]
+  * The [`ONE`][f-o-1-8] constant was added to all fixed-point numbers
+    that can represent the value 1.
   * The following methods were added to all fixed-point numbers and to
     the [`Fixed`][tf-1-8] trait:
       * [`unwrapped_rem`][f-ur-1-8],
@@ -88,10 +94,15 @@ The conversions supported cover the following cases.
       * [`unwrapped_rem_int`][f-uri-1-8]
   * Many methods were marked with the `must_use` attribute.
 
+[f-d-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.FixedI32.html#associatedconstant.DELTA
+[f-o-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.FixedI32.html#associatedconstant.ONE
 [f-ur-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.FixedI32.html#method.unwrapped_rem
 [f-ure-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.FixedI32.html#method.unwrapped_rem_euclid
 [f-uri-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.FixedI32.html#method.unwrapped_rem_int
+[f-z-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.FixedI32.html#associatedconstant.ZERO
 [tf-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/traits/trait.Fixed.html
+[u-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.Unwrapped.html
+[w-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.Wrapping.html
 
 ### Version 1.7.0 news (2021-03-25)
 

RELEASES.md

@@ -8,6 +8,12 @@ as-is, without any warranty. -->
 Version 1.8.0 (unreleased)
 ==========================
 
+  * The following constants were added to all fixed-point numbers, to
+    the [`Fixed`][tf-1-8] trait, and to the [`Wrapping`][w-1-8] and
+    [`Unwrapped`][u-1-8] wrappers:
+      * [`ZERO`][f-z-1-8], [`DELTA`][f-d-1-8]
+  * The [`ONE`][f-o-1-8] constant was added to all fixed-point numbers
+    that can represent the value 1.
   * The following methods were added to all fixed-point numbers and to
     the [`Fixed`][tf-1-8] trait:
       * [`unwrapped_rem`][f-ur-1-8],
@@ -15,10 +21,15 @@ Version 1.8.0 (unreleased)
       * [`unwrapped_rem_int`][f-uri-1-8]
   * Many methods were marked with the `must_use` attribute.
 
+[f-d-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.FixedI32.html#associatedconstant.DELTA
+[f-o-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.FixedI32.html#associatedconstant.ONE
 [f-ur-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.FixedI32.html#method.unwrapped_rem
 [f-ure-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.FixedI32.html#method.unwrapped_rem_euclid
 [f-uri-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.FixedI32.html#method.unwrapped_rem_int
+[f-z-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.FixedI32.html#associatedconstant.ZERO
 [tf-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/traits/trait.Fixed.html
+[u-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.Unwrapped.html
+[w-1-8]: https://tspiteri.gitlab.io/fixed/dev/fixed/struct.Wrapping.html
 
 Version 1.7.0 (2021-03-25)
 ==========================

src/macros_const.rs

@@ -193,6 +193,21 @@ let _ = Fix::LOG2_E;
             where
                 Frac: IsLessOrEqual<$LeEqU_C1, Output = True>,
             {
+                comment! {
+                    "One.
+
+# Examples
+
+```rust
+use fixed::{types::extra::U4, ", $s_fixed, "};
+type Fix = ", $s_fixed, "<U4>;
+assert_eq!(Fix::ONE, Fix::from_num(1));
+```
+";
+                    pub const ONE: $Fixed<Frac> =
+                        $Fixed::from_bits($Fixed::<Frac>::DELTA.to_bits() << Frac::U32);
+                }
+
                 /// τ/4 = 1.57079…
                 pub const FRAC_TAU_4: $Fixed<Frac> = shift!(FRAC_TAU_4, 127, $Fixed<Frac>);
 

src/macros_no_frac.rs

@@ -51,6 +51,36 @@ assert_eq!(Fix::MAX, Fix::from_bits(", $s_inner, "::MAX));
                 pub const MAX: $Fixed<Frac> = Self::from_bits(<$Inner>::MAX);
             }
 
+            comment! {
+                "Zero.
+
+# Examples
+
+```rust
+use fixed::{types::extra::U4, ", $s_fixed, "};
+type Fix = ", $s_fixed, "<U4>;
+assert_eq!(Fix::ZERO, Fix::from_bits(0));
+```
+";
+                pub const ZERO: $Fixed<Frac> = Self::from_bits(0);
+            }
+
+            comment! {
+                "The smallest positive value that can be represented.
+
+# Examples
+
+```rust
+use fixed::{types::extra::U4, ", $s_fixed, "};
+type Fix = ", $s_fixed, "<U4>;
+assert_eq!(Fix::DELTA, Fix::from_bits(1));
+// binary 0.0001 is decimal 0.0625
+assert_eq!(Fix::DELTA, 0.0625);
+```
+";
+                pub const DELTA: $Fixed<Frac> = Self::from_bits(1);
+            }
+
             comment! {
                 if_signed_unsigned!($Signedness, "[`true`]", "[`false`]"),
                 "[`bool`] because the [`", $s_fixed, "`] type is ",

src/traits.rs

@@ -307,6 +307,12 @@ where
     /// The largest value that can be represented.
     const MAX: Self;
 
+    /// Zero.
+    const ZERO: Self;
+
+    /// The smallest positive value that can be represented.
+    const DELTA: Self;
+
     /// [`true`] if the type is signed.
     const IS_SIGNED: bool;
 
@@ -2235,6 +2241,8 @@ macro_rules! impl_fixed {
             type Frac = Frac;
             const MIN: Self = Self::MIN;
             const MAX: Self = Self::MAX;
+            const ZERO: Self = Self::ZERO;
+            const DELTA: Self = Self::DELTA;
             const IS_SIGNED: bool = Self::IS_SIGNED;
             const INT_NBITS: u32 = Self::INT_NBITS;
             const FRAC_NBITS: u32 = Self::FRAC_NBITS;

src/unwrapped.rs

@@ -72,6 +72,26 @@ impl<F: Fixed> Unwrapped<F> {
     /// ```
     pub const MAX: Unwrapped<F> = Unwrapped(F::MAX);
 
+    /// Zero.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use fixed::{types::I16F16, Unwrapped};
+    /// assert_eq!(Unwrapped::<I16F16>::ZERO, Unwrapped(I16F16::ZERO));
+    /// ```
+    pub const ZERO: Unwrapped<F> = Unwrapped(F::ZERO);
+
+    /// The smallest positive value that can be represented.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use fixed::{types::I16F16, Unwrapped};
+    /// assert_eq!(Unwrapped::<I16F16>::DELTA, Unwrapped(I16F16::DELTA));
+    /// ```
+    pub const DELTA: Unwrapped<F> = Unwrapped(F::DELTA);
+
     /// [`true`] if the type is signed.
     ///
     /// # Examples

src/wrapping.rs

@@ -69,6 +69,26 @@ impl<F: Fixed> Wrapping<F> {
     /// ```
     pub const MAX: Wrapping<F> = Wrapping(F::MAX);
 
+    /// Zero.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use fixed::{types::I16F16, Wrapping};
+    /// assert_eq!(Wrapping::<I16F16>::ZERO, Wrapping(I16F16::ZERO));
+    /// ```
+    pub const ZERO: Wrapping<F> = Wrapping(F::ZERO);
+
+    /// The smallest positive value that can be represented.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use fixed::{types::I16F16, Wrapping};
+    /// assert_eq!(Wrapping::<I16F16>::DELTA, Wrapping(I16F16::DELTA));
+    /// ```
+    pub const DELTA: Wrapping<F> = Wrapping(F::DELTA);
+
     /// [`true`] if the type is signed.
     ///
     /// # Examples