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| author | Joshua Nelson <joshua@yottadb.com> | 2021-03-01 11:25:11 -0500 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-03-01 11:25:11 -0500 |
| commit | 9a86a727c5acdf51a3cf062db552a2391da99276 (patch) | |
| tree | ee2b3e874f9ac7f71f2d2dfa18bc93d191bfbeb1 | |
| parent | 687383113949d738f11d26f5cc820db251a7d2e4 (diff) | |
| parent | 2616960be2493e1cdba95cc297bb2dbd520ad7c8 (diff) | |
| download | rust-9a86a727c5acdf51a3cf062db552a2391da99276.tar.gz rust-9a86a727c5acdf51a3cf062db552a2391da99276.zip | |
Rollup merge of #82645 - rkjnsn:patch-3, r=Mark-Simulacrum
Clarify that SyncOnceCell::set blocks. Reading the discussion of this feature, I gained the mistaken impression that neither `set` nor `get` blocked, and thus calling `get` immediately after `set` was not guaranteed to succeed. It turns out that `set` *does* block, guaranteeing that the cell contains a value once `set` returns. This change updates the documentation to state that explicitly. Happy to adjust the wording as desired.
| -rw-r--r-- | library/std/src/lazy.rs | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/library/std/src/lazy.rs b/library/std/src/lazy.rs index aec2a2aa639..974851a8bd6 100644 --- a/library/std/src/lazy.rs +++ b/library/std/src/lazy.rs @@ -177,7 +177,10 @@ impl<T> SyncOnceCell<T> { /// Sets the contents of this cell to `value`. /// - /// Returns `Ok(())` if the cell's value was updated. + /// May block if another thread is currently attempting to initialize the cell. The cell is + /// guaranteed to contain a value when set returns, though not necessarily the one provided. + /// + /// Returns `Ok(())` if the cell's value was set by this call. /// /// # Examples /// |