| // Regression test for #22040. |
| |
| use std::fmt::Debug; |
| |
| trait Expr: Debug + PartialEq { |
| fn print_element_count(&self); |
| } |
| |
| //#[derive(PartialEq)] |
| #[derive(Debug)] |
| struct SExpr<'x> { |
| elements: Vec<Box<dyn Expr + 'x>>, |
| //~^ ERROR E0038 |
| } |
| |
| impl<'x> PartialEq for SExpr<'x> { |
| fn eq(&self, other:&SExpr<'x>) -> bool { |
| println!("L1: {} L2: {}", self.elements.len(), other.elements.len()); |
| |
| let result = self.elements.len() == other.elements.len(); |
| |
| println!("Got compare {}", result); |
| return result; |
| } |
| } |
| |
| impl <'x> SExpr<'x> { |
| fn new() -> SExpr<'x> { return SExpr{elements: Vec::new(),}; } |
| } |
| |
| impl <'x> Expr for SExpr<'x> { |
| fn print_element_count(&self) { |
| println!("element count: {}", self.elements.len()); |
| } |
| } |
| |
| fn main() { |
| let a: Box<dyn Expr> = Box::new(SExpr::new()); |
| //~^ ERROR: `Expr` cannot be made into an object |
| let b: Box<dyn Expr> = Box::new(SExpr::new()); |
| //~^ ERROR: `Expr` cannot be made into an object |
| |
| // assert_eq!(a , b); |
| } |