| #![feature(no_core)] |
| #![no_core] |
| |
| #![feature(lang_items)] |
| #[lang = "sized"] |
| pub trait Sized {} |
| |
| extern "C" { |
| fn printf(s: *const i8, ...); |
| } |
| |
| mod option { |
| enum Option<T> { |
| #[lang = "None"] |
| None, |
| #[lang = "Some"] |
| Some(T), |
| } |
| } |
| |
| pub use option::Option::{self, None, Some}; |
| |
| fn divide(numerator: f64, denominator: f64) -> Option<f64> { |
| if denominator == 0.0 { |
| None |
| } else { |
| Some(numerator / denominator) |
| } |
| } |
| |
| fn main() { |
| let result = divide(2.0, 3.0); |
| |
| match result { |
| Some(x) => unsafe { |
| let a = "Result: %i\n\0"; |
| let b = a as *const str; |
| let c = b as *const i8; |
| |
| printf(c, x); |
| }, |
| None => unsafe { |
| let a = "Cannot divide by 0\n\0"; |
| let b = a as *const str; |
| let c = b as *const i8; |
| |
| printf(c); |
| }, |
| } |
| } |
