add examples

README.md

@@ -1,21 +1,58 @@
 # Measurement
 
-Adds quantities and units to rust to allow unit safe computation
+Adds quantities and units to rust to allow unit safe computation with zero cost abstraction.
 
-**Note**: this crate uses an unstable feature which requires you to add `#![feature(generic_const_exprs)]` and use the nightly compiler
+**Note**: this crate uses an unstable feature which requires you to add `#![feature(generic_const_exprs)]` and use the nightly compiler.
 
-## Define new quantity
+## How to use
+
+Add the `generic_const_exprs` feature by adding `#![feature(generic_const_exprs)]` to your `main.rs` or `lib.rs` file.
+
+```rust
+use measurement::si::{Length, Time, Velocity};
+
+fn main() {
+    let length = Length::new(20.0); // 20m
+    let time = Time::new(5.0); // 5s
+
+    // you can specify the type of the quantity but you don't have to
+    // (see the example below)
+    let velocity: Velocity = length / time;
+
+    println!("{}", velocity.value);
+}
+```
+
+```rust
+use measurement::si::{Mass, Acceleration};
+
+fn main() {
+    let mass = Mass::new(50.0);
+    let acceleration = Acceleration::new(10.0);
+
+    let force = mass * acceleration;
+
+    println!("{}", force.value);
+}
+```
+
+## Define new quantities
 
 currently only three dimensions are supported: Time, Length, Mass
 
 ```rust
 use measurement::{Quantity, Dimension};
 
-pub type Time = Quantity<Dimension<1 /* time */, 0 /* length */, 0 /* mass */>>;
-pub type Length = Quantity<Dimension<0, 1, 0>>;
-pub type Mass = Quantity<Dimension<0, 0, 1>>;
-
-pub type Velocity = Quantity<Dimension<-1, 1, 0>>;
-pub type Acceleration = Quantity<Dimension<-2, 1, 0>>;
+pub type Length                  = Quantity<Dimension<1, 0, 0, 0, 0, 0, 0>>;
+pub type Mass                    = Quantity<Dimension<0, 1, 0, 0, 0, 0, 0>>;
+pub type Time                    = Quantity<Dimension<0, 0, 1, 0, 0, 0, 0>>;
+pub type ElectricalCurrent       = Quantity<Dimension<0, 0, 0, 1, 0, 0, 0>>;
+pub type ThermodynamicTemperatur = Quantity<Dimension<0, 0, 0, 0, 1, 0, 0>>;
+pub type AmountOfSubstance       = Quantity<Dimension<0, 0, 0, 0, 0, 1, 0>>;
+pub type LuminousIntensity       = Quantity<Dimension<0, 0, 0, 0, 0, 0, 1>>;
+
+pub type Velocity     = Quantity<Dimension<1, 0, -1, 0, 0, 0, 0>>;
+pub type Acceleration = Quantity<Dimension<1, 0, -2, 0, 0, 0, 0>>;
+pub type Force        = Quantity<Dimension<1, 1, -2, 0, 0, 0, 0>>;
 
 ```