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Mention pretty debug formatting

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Carol (Nichols || Goulding) 2016-11-23 09:31:54 -05:00
parent 45cb4ebb74
commit 014cddedf3
1 changed files with 12 additions and 2 deletions
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nostarch/chapter05.md
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@ -289,8 +289,18 @@ the following output:
rect1 is Rectangle { length: 50, width: 30 }
```
Nice! It's not the prettiest output, but it shows the values of all the fields
for this instance, which would definitely help during debugging.
Nice! It’s not the prettiest output, but it shows the values of all the fields
for this instance, which would definitely help during debugging. If we want
output that is a bit prettier and easier to read, which can be helpful with
larger structs, we can use `{:#?}` in place of `{:?}` in the `println!` string.
If we use the pretty debug style in this example, the output will look like:
```
rect1 is Rectangle {
length: 50,
width: 30
}
```
There are a number of traits Rust has provided for us to use with the `derive`
annotation that can add useful behavior to our custom types. Those traits and