diff options
| -rw-r--r-- | doc/langref.html.in | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/doc/langref.html.in b/doc/langref.html.in index dc18c0a069..9aa106fb54 100644 --- a/doc/langref.html.in +++ b/doc/langref.html.in @@ -6594,13 +6594,11 @@ const std = @import("std"); const expect = std.testing.expect; test "async and await" { - // Here we have an exception where we do not match an async - // with an await. The test block is not async and so cannot - // have a suspend point in it. - // This is well-defined behavior, and everything is OK here. - // Note however that there would be no way to collect the - // return value of amain, if it were something other than void. - _ = async amain(); + // The test block is not async and so cannot have a suspend + // point in it. By using the nosuspend keyword, we promise that + // the code in amain will finish executing without suspending + // back to the test block. + nosuspend amain(); } fn amain() void { @@ -10799,9 +10797,16 @@ fn readU32Be() u32 {} <pre>{#syntax#}nosuspend{#endsyntax#}</pre> </td> <td> - The {#syntax#}nosuspend{#endsyntax#} keyword. + The {#syntax#}nosuspend{#endsyntax#} keyword can be used in front of a block, statement or expression, to mark a scope where no suspension points are reached. + In particular, inside a {#syntax#}nosuspend{#endsyntax#} scope: + <ul> + <li>Using the {#syntax#}suspend{#endsyntax#} keyword results in a compile error.</li> + <li>Using {#syntax#}await{#endsyntax#} on a function frame which hasn't completed yet results in safety-checked {#link|Undefined Behavior#}.</li> + <li>Calling an async function may result in safety-checked {#link|Undefined Behavior#}, because it's equivalent to <code>await async some_async_fn()</code>, which contains an {#syntax#}await{#endsyntax#}.</li> + </ul> + Code inside a {#syntax#}nosuspend{#endsyntax#} scope does not cause the enclosing function to become an {#link|async function|Async Functions#}. <ul> - <li>TODO add documentation for nosuspend</li> + <li>See also {#link|Async Functions#}</li> </ul> </td> </tr> |