Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 25 insertions, 0 deletions

diff --git a/src/doc/book/listings/ch19-advanced-features/listing-19-27/Cargo.lock b/src/doc/book/listings/ch19-advanced-features/listing-19-27/Cargo.lock
new file mode 100644
index 000000000..b2327c755
--- /dev/null
+++ b/src/doc/book/listings/ch19-advanced-features/listing-19-27/Cargo.lock
@@ -0,0 +1,6 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "functions-example"
+version = "0.1.0"
+
diff --git a/src/doc/book/listings/ch19-advanced-features/listing-19-27/Cargo.toml b/src/doc/book/listings/ch19-advanced-features/listing-19-27/Cargo.toml
new file mode 100644
index 000000000..b196f35b5
--- /dev/null
+++ b/src/doc/book/listings/ch19-advanced-features/listing-19-27/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "functions-example"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
diff --git a/src/doc/book/listings/ch19-advanced-features/listing-19-27/src/main.rs b/src/doc/book/listings/ch19-advanced-features/listing-19-27/src/main.rs
new file mode 100644
index 000000000..91b2cf04b
--- /dev/null
+++ b/src/doc/book/listings/ch19-advanced-features/listing-19-27/src/main.rs
@@ -0,0 +1,13 @@
+fn add_one(x: i32) -> i32 {
+    x + 1
+}
+
+fn do_twice(f: fn(i32) -> i32, arg: i32) -> i32 {
+    f(arg) + f(arg)
+}
+
+fn main() {
+    let answer = do_twice(add_one, 5);
+
+    println!("The answer is: {}", answer);
+}