Function with_callable_target_cache

src/completion/call_resolution.rs:178–187

Activate the thread-local callable target cache. While the returned guard is alive, `resolve_instance_method_callable` caches callable target resolutions by `"FQN::method_lower"` so that the same method on the same class is resolved at most once per diagnostic pass, regardless of how many different chain expressions lead to it.

()

/// diagnostic pass, regardless of how many different chain expressions
/// lead to it.
pub(crate) fn with_callable_target_cache() -> CallableTargetCacheGuard {
    let already_active = CALLABLE_TARGET_CACHE.with(|cell| cell.borrow().is_some());
    if already_active {
        return CallableTargetCacheGuard { owns: false };
    }
    CALLABLE_TARGET_CACHE.with(|cell| {
        *cell.borrow_mut() = Some(HashMap::new());
    });
    CallableTargetCacheGuard { owns: true }
}

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