diff options
Diffstat (limited to 'compiler/rustc_index')
| -rw-r--r-- | compiler/rustc_index/src/lib.rs | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/compiler/rustc_index/src/lib.rs b/compiler/rustc_index/src/lib.rs index 9942c70c4..061c55c01 100644 --- a/compiler/rustc_index/src/lib.rs +++ b/compiler/rustc_index/src/lib.rs @@ -12,7 +12,7 @@ test ) )] -#![cfg_attr(all(not(bootstrap), feature = "nightly"), allow(internal_features))] +#![cfg_attr(feature = "nightly", allow(internal_features))] #[cfg(feature = "nightly")] pub mod bit_set; @@ -29,6 +29,18 @@ pub use {idx::Idx, slice::IndexSlice, vec::IndexVec}; pub use rustc_macros::newtype_index; /// Type size assertion. The first argument is a type and the second argument is its expected size. +/// +/// <div class="warning"> +/// +/// Emitting hard errors from size assertions like this is generally not +/// recommended, especially in libraries, because they can cause build failures if the layout +/// algorithm or dependencies change. Here in rustc we control the toolchain and layout algorithm, +/// so the former is not a problem. For the latter we have a lockfile as rustc is an application and +/// precompiled library. +/// +/// Short version: Don't copy this macro into your own code. Use a `#[test]` instead. +/// +/// </div> #[macro_export] macro_rules! static_assert_size { ($ty:ty, $size:expr) => { |