# SafetyTier....(_:)

- **Module:** SafetyTier
- **Package:** libtmux-swift
- **Language:** Swift
- **Kind:** function
- **Page:** https://libtmux.org/reference/swift/safetytier-(_-)-111j/

```
SafetyTier....(_:)(maximum: Self) -> PartialRangeThrough<Self>
```

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

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]"

- Parameter maximum: The upper bound for the range.

- Precondition: `maximum` must compare equal to itself (i.e. cannot be NaN).