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authorDylan DPC <dylan.dpc@gmail.com>2021-03-19 23:01:38 +0100
committerGitHub <noreply@github.com>2021-03-19 23:01:38 +0100
commit2cc5d727926dd8868ef0f7f62748da9105704402 (patch)
tree76e6f4de5ab0c78fe1bd58f2ca3bbf9fd336fe89
parent1a0e32f4bc30318f4e15d200039bdbc2ea659fdb (diff)
parent19bd0669b45fcc5ce81b8003cafccf318c3cc22e (diff)
Rollup merge of #83254 - jfrimmel:panic_output-stream, r=m-ou-se,joshtriplett
Include output stream in `panic!()` documentation

Fixes #83252.
-rw-r--r--library/core/src/macros/panic.md15
1 files changed, 10 insertions, 5 deletions
diff --git a/library/core/src/macros/panic.md b/library/core/src/macros/panic.md
index 6e502426df9..5127a16bbfd 100644
--- a/library/core/src/macros/panic.md
+++ b/library/core/src/macros/panic.md
@@ -9,11 +9,15 @@ tests. `panic!` is closely tied with the `unwrap` method of both
 [`Option`][ounwrap] and [`Result`][runwrap] enums. Both implementations call
 `panic!` when they are set to [`None`] or [`Err`] variants.
 
-This macro is used to inject panic into a Rust thread, causing the thread to
-panic entirely. This macro panics with a string and uses the [`format!`] syntax
-for building the message.
-
-Each thread's panic can be reaped as the [`Box`]`<`[`Any`]`>` type,
+When using `panic!()` you can specify a string payload, that is built using
+the [`format!`] syntax. That payload is used when injecting the panic into
+the calling Rust thread, causing the thread to panic entirely.
+
+The behavior of the default `std` hook, i.e. the code that runs directly
+after the panic is invoked, is to print the message payload to
+`stderr` along with the file/line/column information of the `panic!()`
+call. You can override the panic hook using [`std::panic::set_hook()`].
+Inside the hook a panic can be accessed as a `&dyn Any + Send`,
 which contains either a `&str` or `String` for regular `panic!()` invocations.
 To panic with a value of another other type, [`panic_any`] can be used.
 
@@ -26,6 +30,7 @@ See also the macro [`compile_error!`], for raising errors during compilation.
 
 [ounwrap]: Option::unwrap
 [runwrap]: Result::unwrap
+[`std::panic::set_hook()`]: ../std/panic/fn.set_hook.html
 [`panic_any`]: ../std/panic/fn.panic_any.html
 [`Box`]: ../std/boxed/struct.Box.html
 [`Any`]: crate::any::Any