Avoid specifying "last import wins" for MBEs #2057
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traviscross commented Oct 22, 2025
Comment on lines +395 to +396
| > [!NOTE] | ||
| > `rustc` currently prefers the last macro in case of conflict. Don't rely on this. This behavior is unusual, as imports in Rust are generally order-independent. This behavior of `macro_use` may change in the future. |
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If there's a good issue to cite for this, we can cite it here.
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I've opened rust-lang/rust#148025 for this.
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Thanks. Added it here.
Currently, for `macro_use`, the last macro imported wins. This may be something that we consider to be a bug. Rather than documenting this normatively, then, let's stay normatively silent on that behavior and document the details of the situation with `rustc` in an admonition.
traviscross force-pushed the TC/loosen-mbe-last-macro-imported-wins branch from 97cadcf to 5b19599 Compare Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
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Currently, for
macro_use, the last macro imported wins. This may be something that we consider to be a bug. Rather than documenting this normatively, then, let's stay normatively silent on that behavior and document the details of the situation withrustcin an admonition.cc @ehuss @petrochenkov #1886 (comment)