Make the interface more Newtype like

Cargo.toml

@@ -16,9 +16,13 @@ typenum = "1.16"
 num-traits = { version = "0.2", default-features = false }
 defmt = { version = "0.3", optional = true }
 fixed = { version = "1.23.0", optional = true }
+serde = { version = "1.0", default-features = false, features = [
+  "derive",
+], optional = true }
 
 [features]
 default = ["std"]
 defmt = ["dep:defmt"]
 fixed = ["dep:fixed"]
 std = ["num-traits/std"]
+serde = ["dep:serde"]

src/lib.rs

@@ -2,6 +2,8 @@
 mod display;
 pub mod types;
 
+#[cfg(feature = "nightly")]
+use core::marker::Destruct;
 use core::{
     marker::PhantomData,
     ops::{
@@ -17,6 +19,7 @@ use typenum::{int::Z0, op, Integer};
 use types::Unit;
 
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Copy)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct SiUnit<T, Second, Metre, Kilogram, Ampere, Kelvin, Mole, Candela>
 where
     Second: Integer,
@@ -28,13 +31,23 @@ where
     Candela: Integer,
 {
     value: T,
-    _s: PhantomData<Second>,
+    _marker: PhantomData<(Second, Metre, Kilogram, Ampere, Kelvin, Mole, Candela)>,
-    _m: PhantomData<Metre>,
+}
-    _kg: PhantomData<Kilogram>,
+
-    _a: PhantomData<Ampere>,
+#[allow(non_snake_case)]
-    _k: PhantomData<Kelvin>,
+pub fn SiUnit<T, Second, Metre, Kilogram, Ampere, Kelvin, Mole, Candela>(
-    _mol: PhantomData<Mole>,
+    value: T,
-    _cd: PhantomData<Candela>,
+) -> SiUnit<T, Second, Metre, Kilogram, Ampere, Kelvin, Mole, Candela>
+where
+    Second: Integer,
+    Metre: Integer,
+    Kilogram: Integer,
+    Ampere: Integer,
+    Kelvin: Integer,
+    Mole: Integer,
+    Candela: Integer,
+{
+    SiUnit::new(value)
 }
 
 impl<T, Second, Metre, Kilogram, Ampere, Kelvin, Mole, Candela> Deref
@@ -595,13 +608,7 @@ where
     pub const fn new(value: T) -> Self {
         Self {
             value,
-            _s: PhantomData,
+            _marker: PhantomData,
-            _m: PhantomData,
-            _kg: PhantomData,
-            _a: PhantomData,
-            _k: PhantomData,
-            _mol: PhantomData,
-            _cd: PhantomData,
         }
     }
 }

src/types.rs

@@ -1,10 +1,26 @@
 use crate::SiUnit;
 use typenum::consts::{N1, N2, N3, P1, P2, P3, P4, Z0};
 
+macro_rules! unit {
+    ($acronym: ident -> $second: ty, $metre: ty, $kilogram: ty, $ampere: ty, $kelvin: ty, $mole: ty, $candela: ty $(; $doc: literal)?) => {
+        $(
+        #[doc = $doc]
+        )?
+        pub type $acronym<T> = SiUnit<T, $second, $metre, $kilogram, $ampere, $kelvin, $mole, $candela>;
+        #[allow(non_snake_case)]
+        $(
+        #[doc = $doc]
+        )?
+        pub const fn $acronym<T>(value: T) -> $acronym<T> {
+            $acronym::new(value)
+        }
+    };
+}
+
 // Base units
-pub type Unit<T> = SiUnit<T, Z0, Z0, Z0, Z0, Z0, Z0, Z0>;
+unit!(Unit -> Z0, Z0, Z0, Z0, Z0, Z0, Z0);
-/// time
+unit!(Second -> P1, Z0, Z0, Z0, Z0, Z0, Z0; "time");
-pub type Second<T> = SiUnit<T, P1, Z0, Z0, Z0, Z0, Z0, Z0>;
+//pub type Second<T> = SiUnit<T, P1, Z0, Z0, Z0, Z0, Z0, Z0>;
 /// length
 pub type Metre<T> = SiUnit<T, Z0, P1, Z0, Z0, Z0, Z0, Z0>;
 /// mass