rust/tests/ui/coercion/any-trait-object-debug-12744.rs

//! Regression test for https://github.com/rust-lang/rust/issues/12744

//@ run-pass
fn main() {
    fn test() -> Box<dyn std::any::Any + 'static> { Box::new(1) }
    println!("{:?}", test())
}
comments 2025-07-24 17:22:54 +05:00			`//! Regression test for https://github.com/rust-lang/rust/issues/12744`

[AUTO-GENERATED] Migrate ui tests from `//` to `//@` directives 2024-02-16 20:02:50 +00:00			`//@ run-pass`
Add tests for E-needstest issues 2014-12-07 15:22:06 +00:00			`fn main() {`
Update run-pass test suite to use dyn 2019-05-28 14:47:21 -04:00			`fn test() -> Box<dyn std::any::Any + 'static> { Box::new(1) }`
core: split into fmt::Show and fmt::String fmt::Show is for debugging, and can and should be implemented for all public types. This trait is used with `{:?}` syntax. There still exists #[derive(Show)]. fmt::String is for types that faithfully be represented as a String. Because of this, there is no way to derive fmt::String, all implementations must be purposeful. It is used by the default format syntax, `{}`. This will break most instances of `{}`, since that now requires the type to impl fmt::String. In most cases, replacing `{}` with `{:?}` is the correct fix. Types that were being printed specifically for users should receive a fmt::String implementation to fix this. Part of #20013 [breaking-change] 2014-12-20 00:09:35 -08:00			`println!("{:?}", test())`
Add tests for E-needstest issues 2014-12-07 15:22:06 +00:00			`}`