diff options
Diffstat (limited to 'src/doc/book/listings/ch10-generic-types-traits-and-lifetimes/no-listing-06-impl-trait-returns-one-type')
3 files changed, 69 insertions, 0 deletions
diff --git a/src/doc/book/listings/ch10-generic-types-traits-and-lifetimes/no-listing-06-impl-trait-returns-one-type/Cargo.lock b/src/doc/book/listings/ch10-generic-types-traits-and-lifetimes/no-listing-06-impl-trait-returns-one-type/Cargo.lock new file mode 100644 index 000000000..2835471f0 --- /dev/null +++ b/src/doc/book/listings/ch10-generic-types-traits-and-lifetimes/no-listing-06-impl-trait-returns-one-type/Cargo.lock @@ -0,0 +1,7 @@ +# This file is automatically @generated by Cargo. +# It is not intended for manual editing. +version = 3 + +[[package]] +name = "aggregator" +version = "0.1.0" diff --git a/src/doc/book/listings/ch10-generic-types-traits-and-lifetimes/no-listing-06-impl-trait-returns-one-type/Cargo.toml b/src/doc/book/listings/ch10-generic-types-traits-and-lifetimes/no-listing-06-impl-trait-returns-one-type/Cargo.toml new file mode 100644 index 000000000..46f46a7f4 --- /dev/null +++ b/src/doc/book/listings/ch10-generic-types-traits-and-lifetimes/no-listing-06-impl-trait-returns-one-type/Cargo.toml @@ -0,0 +1,6 @@ +[package] +name = "aggregator" +version = "0.1.0" +edition = "2021" + +[dependencies] diff --git a/src/doc/book/listings/ch10-generic-types-traits-and-lifetimes/no-listing-06-impl-trait-returns-one-type/src/lib.rs b/src/doc/book/listings/ch10-generic-types-traits-and-lifetimes/no-listing-06-impl-trait-returns-one-type/src/lib.rs new file mode 100644 index 000000000..7cd81d4c3 --- /dev/null +++ b/src/doc/book/listings/ch10-generic-types-traits-and-lifetimes/no-listing-06-impl-trait-returns-one-type/src/lib.rs @@ -0,0 +1,56 @@ +pub trait Summary { + fn summarize(&self) -> String; +} + +pub struct NewsArticle { + pub headline: String, + pub location: String, + pub author: String, + pub content: String, +} + +impl Summary for NewsArticle { + fn summarize(&self) -> String { + format!("{}, by {} ({})", self.headline, self.author, self.location) + } +} + +pub struct Tweet { + pub username: String, + pub content: String, + pub reply: bool, + pub retweet: bool, +} + +impl Summary for Tweet { + fn summarize(&self) -> String { + format!("{}: {}", self.username, self.content) + } +} + +// ANCHOR: here +fn returns_summarizable(switch: bool) -> impl Summary { + if switch { + NewsArticle { + headline: String::from( + "Penguins win the Stanley Cup Championship!", + ), + location: String::from("Pittsburgh, PA, USA"), + author: String::from("Iceburgh"), + content: String::from( + "The Pittsburgh Penguins once again are the best \ + hockey team in the NHL.", + ), + } + } else { + Tweet { + username: String::from("horse_ebooks"), + content: String::from( + "of course, as you probably already know, people", + ), + reply: false, + retweet: false, + } + } +} +// ANCHOR_END: here |