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swift-mirror/stdlib/public/core/Algorithm.swift
2025-03-13 09:58:09 -07:00

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Swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
/// Returns the lesser of two comparable values.
///
/// - Parameters:
/// - x: A value to compare.
/// - y: Another value to compare.
/// - Returns: The lesser of `x` and `y`. If `x` is equal to `y`, returns `x`.
@inlinable // protocol-only
public func min<T: Comparable>(_ x: T, _ y: T) -> T {
// In case `x == y` we pick `x`.
// This preserves any pre-existing order in case `T` has identity,
// which is important for e.g. the stability of sorting algorithms.
// `(min(x, y), max(x, y))` should return `(x, y)` in case `x == y`.
return y < x ? y : x
}
/// Returns the least argument passed.
///
/// - Parameters:
/// - x: A value to compare.
/// - y: Another value to compare.
/// - z: A third value to compare.
/// - rest: Zero or more additional values.
/// - Returns: The least of all the arguments. If there are multiple equal
/// least arguments, the result is the first one.
@inlinable // protocol-only
public func min<T: Comparable>(_ x: T, _ y: T, _ z: T, _ rest: T...) -> T {
var minValue = min(min(x, y), z)
// In case `value == minValue`, we pick `minValue`. See min(_:_:).
for value in rest where value < minValue {
minValue = value
}
return minValue
}
/// Returns the greater of two comparable values.
///
/// - Parameters:
/// - x: A value to compare.
/// - y: Another value to compare.
/// - Returns: The greater of `x` and `y`. If `x` is equal to `y`, returns `y`.
@inlinable // protocol-only
public func max<T: Comparable>(_ x: T, _ y: T) -> T {
// In case `x == y`, we pick `y`. See min(_:_:).
return y >= x ? y : x
}
/// Returns the greatest argument passed.
///
/// - Parameters:
/// - x: A value to compare.
/// - y: Another value to compare.
/// - z: A third value to compare.
/// - rest: Zero or more additional values.
/// - Returns: The greatest of all the arguments. If there are multiple equal
/// greatest arguments, the result is the last one.
@inlinable // protocol-only
public func max<T: Comparable>(_ x: T, _ y: T, _ z: T, _ rest: T...) -> T {
var maxValue = max(max(x, y), z)
// In case `value == maxValue`, we pick `value`. See min(_:_:).
for value in rest where value >= maxValue {
maxValue = value
}
return maxValue
}