feat(errors5): add simpler explanation for box dyn

This commit is contained in:
mokou 2022-08-03 17:31:42 +02:00
parent 977a167335
commit af301a2efe
2 changed files with 3 additions and 1 deletions

2
Cargo.lock generated
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@ -459,7 +459,7 @@ checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
[[package]] [[package]]
name = "rustlings" name = "rustlings"
version = "4.8.0" version = "5.0.0"
dependencies = [ dependencies = [
"argh", "argh",
"assert_cmd", "assert_cmd",

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@ -4,6 +4,8 @@
// This exercise uses some concepts that we won't get to until later in the course, like `Box` and the // This exercise uses some concepts that we won't get to until later in the course, like `Box` and the
// `From` trait. It's not important to understand them in detail right now, but you can read ahead if you like. // `From` trait. It's not important to understand them in detail right now, but you can read ahead if you like.
// For now, think of the `Box<dyn ...>` type as an "I want anything that does ???" type, which, given
// Rust's usual standards for runtime safety, should strike you as somewhat lenient!
// In short, this particular use case for boxes is for when you want to own a value and you care only that it is a // In short, this particular use case for boxes is for when you want to own a value and you care only that it is a
// type which implements a particular trait. To do so, The Box is declared as of type Box<dyn Trait> where Trait is the trait // type which implements a particular trait. To do so, The Box is declared as of type Box<dyn Trait> where Trait is the trait