75a9be609e
`concat_idents` has been around unstably for a long time, but there is
now a better (but still unstable) way to join identifiers using
`${concat(...)}` syntax with `macro_metavar_expr_concat`. This resolves
a lot of the problems with `concat_idents` and is on a better track
toward stabilization, so there is no need to keep both versions around.
`concat_idents!` still has a lot of use in the ecosystem so deprecate it
before removing, as discussed in [1].
Link: https://github.com/rust-lang/rust/issues/124225
[1]: https://rust-lang.zulipchat.com/#narrow/channel/219381-t-libs/topic/Removing.20.60concat_idents.60
21 lines
863 B
Plaintext
21 lines
863 B
Plaintext
error[E0658]: use of unstable library feature `concat_idents`: `concat_idents` is not stable enough for use and is subject to change
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--> $DIR/feature-gate-concat_idents2.rs:4:5
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LL | concat_idents!(a, b);
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| ^^^^^^^^^^^^^
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= note: see issue #29599 <https://github.com/rust-lang/rust/issues/29599> for more information
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= help: add `#![feature(concat_idents)]` to the crate attributes to enable
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= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
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error[E0425]: cannot find value `ab` in this scope
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--> $DIR/feature-gate-concat_idents2.rs:4:5
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LL | concat_idents!(a, b);
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| ^^^^^^^^^^^^^^^^^^^^ not found in this scope
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error: aborting due to 2 previous errors
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Some errors have detailed explanations: E0425, E0658.
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For more information about an error, try `rustc --explain E0425`.
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