Type OperatorSwiftNIOConcurrencyHelpersSwift

# ...(_:)

Returns a partial range up to, and including, its upper bound.

Available because

`Self`

conforms to`Comparable`

.

`static func ... (maximum: Self) -> PartialRangeThrough<Self>`

## Parameters

- maximum
The upper bound for the range.

## Overview

Use the prefix closed range operator (prefix `...`

) to create a partial range of any type that conforms to the `Comparable`

protocol. This example creates a `PartialRangeThrough<Double>`

instance that includes any value less than or equal to `5.0`

.

```
let throughFive = ...5.0
throughFive.contains(4.0) // true
throughFive.contains(5.0) // true
throughFive.contains(6.0) // false
```

You can use this type of partial range of a collection’s indices to represent the range from the start of the collection up to, and including, the partial range’s upper bound.

```
let numbers = [10, 20, 30, 40, 50, 60, 70]
print(numbers[...3])
// Prints "[10, 20, 30, 40]"
```