0cc00c48d2
std: Add a variant of thread locals with const init This commit adds a variant of the `thread_local!` macro as a new `thread_local_const_init!` macro which requires that the initialization expression is constant (e.g. could be stuck into a `const` if so desired). This form of thread local allows for a more efficient implementation of `LocalKey::with` both if the value has a destructor and if it doesn't. If the value doesn't have a destructor then `with` should desugar to exactly as-if you use `#[thread_local]` given sufficient inlining. The purpose of this new form of thread locals is to precisely be equivalent to `#[thread_local]` on platforms where possible for values which fit the bill (those without destructors). This should help close the gap in performance between `thread_local!`, which is safe, relative to `#[thread_local]`, which is not easy to use in a portable fashion. |
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| .. | ||
| alloc | ||
| backtrace@710fc18ddc | ||
| core | ||
| panic_abort | ||
| panic_unwind | ||
| proc_macro | ||
| profiler_builtins | ||
| rtstartup | ||
| rustc-std-workspace-alloc | ||
| rustc-std-workspace-core | ||
| rustc-std-workspace-std | ||
| std | ||
| stdarch@19f5459dd0 | ||
| term | ||
| test | ||
| unwind | ||