diff options
Diffstat (limited to 'src/doc/book/listings/ch04-understanding-ownership/listing-04-03')
4 files changed, 36 insertions, 0 deletions
diff --git a/src/doc/book/listings/ch04-understanding-ownership/listing-04-03/Cargo.lock b/src/doc/book/listings/ch04-understanding-ownership/listing-04-03/Cargo.lock new file mode 100644 index 000000000..9e4e62ddf --- /dev/null +++ b/src/doc/book/listings/ch04-understanding-ownership/listing-04-03/Cargo.lock @@ -0,0 +1,4 @@ +[[package]] +name = "ownership" +version = "0.1.0" + diff --git a/src/doc/book/listings/ch04-understanding-ownership/listing-04-03/Cargo.toml b/src/doc/book/listings/ch04-understanding-ownership/listing-04-03/Cargo.toml new file mode 100644 index 000000000..e8847526d --- /dev/null +++ b/src/doc/book/listings/ch04-understanding-ownership/listing-04-03/Cargo.toml @@ -0,0 +1,6 @@ +[package] +name = "ownership" +version = "0.1.0" +edition = "2021" + +[dependencies] diff --git a/src/doc/book/listings/ch04-understanding-ownership/listing-04-03/rustfmt-ignore b/src/doc/book/listings/ch04-understanding-ownership/listing-04-03/rustfmt-ignore new file mode 100644 index 000000000..9a53c718a --- /dev/null +++ b/src/doc/book/listings/ch04-understanding-ownership/listing-04-03/rustfmt-ignore @@ -0,0 +1,3 @@ +We have some weird comments pointing out borrowing scopes that we don't want to change; +unfortunately I haven't found a way to skip them with rustfmt that works so for now we're going to +manually skip those listings. See: https://github.com/rust-lang/rustfmt/issues/4028 diff --git a/src/doc/book/listings/ch04-understanding-ownership/listing-04-03/src/main.rs b/src/doc/book/listings/ch04-understanding-ownership/listing-04-03/src/main.rs new file mode 100644 index 000000000..b001cc5f4 --- /dev/null +++ b/src/doc/book/listings/ch04-understanding-ownership/listing-04-03/src/main.rs @@ -0,0 +1,23 @@ +fn main() { + let s = String::from("hello"); // s comes into scope + + takes_ownership(s); // s's value moves into the function... + // ... and so is no longer valid here + + let x = 5; // x comes into scope + + makes_copy(x); // x would move into the function, + // but i32 is Copy, so it's okay to still + // use x afterward + +} // Here, x goes out of scope, then s. But because s's value was moved, nothing + // special happens. + +fn takes_ownership(some_string: String) { // some_string comes into scope + println!("{}", some_string); +} // Here, some_string goes out of scope and `drop` is called. The backing + // memory is freed. + +fn makes_copy(some_integer: i32) { // some_integer comes into scope + println!("{}", some_integer); +} // Here, some_integer goes out of scope. Nothing special happens. |