rust/example/std_example.rs
2019-07-26 11:30:39 +02:00

79 lines
2.4 KiB
Rust

#![feature(core_intrinsics)]
use std::io::Write;
use std::intrinsics;
fn main() {
let _ = ::std::iter::repeat('a' as u8).take(10).collect::<Vec<_>>();
let stderr = ::std::io::stderr();
let mut stderr = stderr.lock();
writeln!(stderr, "some {} text", "<unknown>").unwrap();
let _ = std::process::Command::new("true").env("c", "d").spawn();
println!("cargo:rustc-link-lib=z");
static ONCE: std::sync::Once = std::sync::ONCE_INIT;
ONCE.call_once(|| {});
LoopState::Continue(()) == LoopState::Break(());
// Make sure ByValPair values with differently sized components are correctly passed
map(None::<(u8, Box<Instruction>)>);
println!("{}", 2.3f32.exp());
println!("{}", 2.3f32.exp2());
println!("{}", 2.3f32.abs());
println!("{}", 2.3f32.sqrt());
println!("{}", 2.3f32.floor());
println!("{}", 2.3f32.ceil());
println!("{}", 2.3f32.min(1.0));
println!("{}", 2.3f32.max(1.0));
assert_eq!(0b0000000000000000000000000010000010000000000000000000000000000000_0000000000100000000000000000000000001000000000000100000000000000u128.leading_zeros(), 26);
assert_eq!(0b0000000000000000000000000010000000000000000000000000000000000000_0000000000000000000000000000000000001000000000000000000010000000u128.trailing_zeros(), 7);
checked_div_i128(0i128, 2i128);
checked_div_u128(0u128, 2u128);
assert_eq!(1u128 + 2, 3);
assert_eq!(0b100010000000000000000000000000000u128 >> 10, 0b10001000000000000000000u128);
assert_eq!(0xFEDCBA987654321123456789ABCDEFu128 >> 64, 0xFEDCBA98765432u128);
assert_eq!(0xFEDCBA987654321123456789ABCDEFu128 as i128 >> 64, 0xFEDCBA98765432i128);
assert_eq!(353985398u128 * 932490u128, 330087843781020u128);
}
#[derive(PartialEq)]
enum LoopState {
Continue(()),
Break(())
}
pub enum Instruction {
Increment,
Loop,
}
fn map(a: Option<(u8, Box<Instruction>)>) -> Option<Box<Instruction>> {
match a {
None => None,
Some((_, instr)) => Some(instr),
}
}
fn checked_div_i128(lhs: i128, rhs: i128) -> Option<i128> {
if rhs == 0 || (lhs == -170141183460469231731687303715884105728 && rhs == -1) {
None
} else {
Some(unsafe { intrinsics::unchecked_div(lhs, rhs) })
}
}
fn checked_div_u128(lhs: u128, rhs: u128) -> Option<u128> {
match rhs {
0 => None,
rhs => Some(unsafe { intrinsics::unchecked_div(lhs, rhs) })
}
}