1 error[E0658]: use of unstable library feature 'concat_idents': `concat_idents` is not stable enough for use and is subject to change
2 --> $DIR/feature-gate-concat_idents2.rs:2:5
4 LL | concat_idents!(a, b);
7 = note: see issue #29599 <https://github.com/rust-lang/rust/issues/29599> for more information
8 = help: add `#![feature(concat_idents)]` to the crate attributes to enable
10 error[E0425]: cannot find value `ab` in this scope
11 --> $DIR/feature-gate-concat_idents2.rs:2:5
13 LL | concat_idents!(a, b);
14 | ^^^^^^^^^^^^^^^^^^^^^ not found in this scope
16 = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
18 error: aborting due to 2 previous errors
20 Some errors have detailed explanations: E0425, E0658.
21 For more information about an error, try `rustc --explain E0425`.