diff options
Diffstat (limited to 'src/doc/book/listings/ch09-error-handling/listing-09-11')
3 files changed, 28 insertions, 0 deletions
diff --git a/src/doc/book/listings/ch09-error-handling/listing-09-11/Cargo.lock b/src/doc/book/listings/ch09-error-handling/listing-09-11/Cargo.lock new file mode 100644 index 000000000..7320ae639 --- /dev/null +++ b/src/doc/book/listings/ch09-error-handling/listing-09-11/Cargo.lock @@ -0,0 +1,7 @@ +# This file is automatically @generated by Cargo. +# It is not intended for manual editing. +version = 3 + +[[package]] +name = "error-handling" +version = "0.1.0" diff --git a/src/doc/book/listings/ch09-error-handling/listing-09-11/Cargo.toml b/src/doc/book/listings/ch09-error-handling/listing-09-11/Cargo.toml new file mode 100644 index 000000000..c496db783 --- /dev/null +++ b/src/doc/book/listings/ch09-error-handling/listing-09-11/Cargo.toml @@ -0,0 +1,6 @@ +[package] +name = "error-handling" +version = "0.1.0" +edition = "2021" + +[dependencies] diff --git a/src/doc/book/listings/ch09-error-handling/listing-09-11/src/main.rs b/src/doc/book/listings/ch09-error-handling/listing-09-11/src/main.rs new file mode 100644 index 000000000..bd5322786 --- /dev/null +++ b/src/doc/book/listings/ch09-error-handling/listing-09-11/src/main.rs @@ -0,0 +1,15 @@ +// ANCHOR: here +fn last_char_of_first_line(text: &str) -> Option<char> { + text.lines().next()?.chars().last() +} +// ANCHOR_END: here + +fn main() { + assert_eq!( + last_char_of_first_line("Hello, world\nHow are you today?"), + Some('d') + ); + + assert_eq!(last_char_of_first_line(""), None); + assert_eq!(last_char_of_first_line("\nhi"), None); +} |