From 9775ac60dcc92dbb04861863a69eacfafeea5c4c Mon Sep 17 00:00:00 2001
From: Camelid <camelidcamel@gmail.com>
Date: Thu, 22 Oct 2020 14:22:09 -0700
Subject: [PATCH] Document inline-const in the Unstable Book

---
 .../src/language-features/inline-const.md     | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 src/doc/unstable-book/src/language-features/inline-const.md

diff --git a/src/doc/unstable-book/src/language-features/inline-const.md b/src/doc/unstable-book/src/language-features/inline-const.md
new file mode 100644
index 0000000000000..00e1c79ca3ff3
--- /dev/null
+++ b/src/doc/unstable-book/src/language-features/inline-const.md
@@ -0,0 +1,45 @@
+# `inline_const`
+
+The tracking issue for this feature is: [#76001]
+
+------
+
+This feature allows you to use inline constant expressions. For example, you can
+turn this code:
+
+```rust
+# fn add_one(x: i32) -> i32 { x + 1 }
+const MY_COMPUTATION: i32 = 1 + 2 * 3 / 4;
+
+fn main() {
+    let x = add_one(MY_COMPUTATION);
+}
+```
+
+into this code:
+
+```rust
+#![feature(inline_const)]
+
+# fn add_one(x: i32) -> i32 { x + 1 }
+fn main() {
+    let x = add_one(const { 1 + 2 * 3 / 4 });
+}
+```
+
+You can also use inline constant expressions in patterns:
+
+```rust
+#![feature(inline_const)]
+
+const fn one() -> i32 { 1 }
+
+let some_int = 3;
+match some_int {
+    const { 1 + 2 } => println!("Matched 1 + 2"),
+    const { one() } => println!("Matched const fn returning 1"),
+    _ => println!("Didn't match anything :("),
+}
+```
+
+[#76001]: https://github.com/rust-lang/rust/issues/76001