Define a primitive data type: Difference between revisions

=={{header|Swift}}==

<lang swift>struct SmallInt {

var value: Int

init(value: Int) {

guard value >= 1 && value <= 10 else {

fatalError("SmallInts must be in the range [1, 10]")

}

self.value = value

}

static func +(_ lhs: SmallInt, _ rhs: SmallInt) -> SmallInt { SmallInt(value: lhs.value + rhs.value) }

static func -(_ lhs: SmallInt, _ rhs: SmallInt) -> SmallInt { SmallInt(value: lhs.value - rhs.value) }

static func *(_ lhs: SmallInt, _ rhs: SmallInt) -> SmallInt { SmallInt(value: lhs.value * rhs.value) }

static func /(_ lhs: SmallInt, _ rhs: SmallInt) -> SmallInt { SmallInt(value: lhs.value / rhs.value) }

}

extension SmallInt: ExpressibleByIntegerLiteral {

public init(integerLiteral value: Int) { self.init(value: value) }

}

extension SmallInt: CustomStringConvertible {

public var description: String { "\(value)" }

}

let a: SmallInt = 1

let b: SmallInt = 9

let c: SmallInt = 10

let d: SmallInt = 2

print(a + b)

print(c - b)

print(a * c)

print(c / d)

print(a + c)</lang>

{{out}}

<pre>10

1

10

5

Runner/main.swift:17: Fatal error: SmallInts must be in the range [1, 10]

Illegal instruction: 4</pre>