rust/tests/ui/object-safety/object-safety-issue-22040.rs

45 lines
1.0 KiB
Rust

// 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);
}