rust/tests/ui/issues/issue-6458-2.rs

fn main() {
    // Unconstrained type:
    format!("{:?}", None);
    //~^ ERROR type annotations needed [E0282]
}
testsuite: Tests for #6458. Closes #6458 2013-08-12 20:47:02 +00:00			`fn main() {`
Update error messages in compile-fail tests 2014-09-12 14:45:39 +00:00			`// Unconstrained type:`
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 08:09:35 +00:00			`format!("{:?}", None);`
Add a new ui test and update existing ones 2017-02-02 21:35:31 +00:00			`//~^ ERROR type annotations needed [E0282]`
testsuite: Tests for #6458. Closes #6458 2013-08-12 20:47:02 +00:00			`}`