// Copyright 2017 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. // compile-flags: --edition 2018 #![feature(catch_expr)] struct catch {} pub fn main() { let catch_result: Option<_> = try { let x = 5; x }; assert_eq!(catch_result, Some(5)); let mut catch = true; while catch { catch = false; } assert_eq!(catch, false); catch = if catch { false } else { true }; assert_eq!(catch, true); match catch { _ => {} }; let catch_err: Result<_, i32> = try { Err(22)?; 1 }; assert_eq!(catch_err, Err(22)); let catch_okay: Result = try { if false { Err(25)?; } Ok::<(), i32>(())?; 28 }; assert_eq!(catch_okay, Ok(28)); let catch_from_loop: Result = try { for i in 0..10 { if i < 5 { Ok::(i)?; } else { Err(i)?; } } 22 }; assert_eq!(catch_from_loop, Err(5)); let cfg_init; let _res: Result<(), ()> = try { cfg_init = 5; }; assert_eq!(cfg_init, 5); let cfg_init_2; let _res: Result<(), ()> = try { cfg_init_2 = 6; Err(())?; }; assert_eq!(cfg_init_2, 6); let my_string = "test".to_string(); let res: Result<&str, ()> = try { // Unfortunately, deref doesn't fire here (#49356) &my_string[..] }; assert_eq!(res, Ok("test")); let my_opt: Option<_> = try { () }; assert_eq!(my_opt, Some(())); let my_opt: Option<_> = try { }; assert_eq!(my_opt, Some(())); }