Make the interface more Newtype like

src/lib.rs

@@ -31,15 +31,13 @@ where
     Candela: Integer,
 {
     value: T,
-    _s: PhantomData<Second>,
-    _m: PhantomData<Metre>,
-    _kg: PhantomData<Kilogram>,
-    _a: PhantomData<Ampere>,
-    _k: PhantomData<Kelvin>,
-    _mol: PhantomData<Mole>,
-    _cd: PhantomData<Candela>,
+    _marker: PhantomData<(Second, Metre, Kilogram, Ampere, Kelvin, Mole, Candela)>,
 }
 
+#[allow(non_snake_case)]
+pub fn SiUnit<T, Second, Metre, Kilogram, Ampere, Kelvin, Mole, Candela>(
+    value: T,
+) -> SiUnit<T, Second, Metre, Kilogram, Ampere, Kelvin, Mole, Candela>
 where
     Second: Integer,
     Metre: Integer,
@@ -49,6 +47,7 @@ where
     Mole: Integer,
     Candela: Integer,
 {
+    SiUnit::new(value)
 }
 
 impl<T, Second, Metre, Kilogram, Ampere, Kelvin, Mole, Candela> Deref
@@ -609,13 +608,7 @@ where
     pub const fn new(value: T) -> Self {
         Self {
             value,
-            _s: PhantomData,
-            _m: PhantomData,
-            _kg: PhantomData,
-            _a: PhantomData,
-            _k: PhantomData,
-            _mol: PhantomData,
-            _cd: PhantomData,
+            _marker: 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>;
-/// time
-pub type Second<T> = SiUnit<T, P1, Z0, Z0, Z0, Z0, Z0, Z0>;
+unit!(Unit -> Z0, Z0, Z0, Z0, Z0, Z0, Z0);
+unit!(Second -> P1, Z0, Z0, Z0, Z0, Z0, Z0; "time");
+//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