Uses `strwrap()`

to split long labels across multiple lines.

## Value

All `label_()`

functions return a "labelling" function, i.e. a function that
takes a vector `x`

and returns a character vector of `length(x)`

giving a
label for each input value.

Labelling functions are designed to be used with the `labels`

argument of
ggplot2 scales. The examples demonstrate their use with x scales, but
they work similarly for all scales, including those that generate legends
rather than axes.

## See also

Other labels for discrete scales:
`label_parse()`

## Examples

```
x <- c(
"this is a long label",
"this is another long label",
"this a label this is even longer"
)
demo_discrete(x)
#> scale_x_discrete()
demo_discrete(x, labels = label_wrap(10))
#> scale_x_discrete(labels = label_wrap(10))
demo_discrete(x, labels = label_wrap(20))
#> scale_x_discrete(labels = label_wrap(20))
```