Defining Generic Functions and Structs
Carlo Milanesi · Apress eBooks · 2018
Rust performs a strict data type check, so when you define a function that uses an argument of a certain type, say fn square_root(x: f32) -> f32, the code that invokes such a function must pass to it an expression of exactly that type, like in square_root(45.2f32), or it must perform explicit conversions every time that function is used, like in square_root(45.2f64 as f32). You cannot pass a different type, like in square_root(45.2f64).