Sequence+Bool.swift

// Snippets SequenceType+Bool.swift
//
// Copyright © 2016, Roy Ratcliffe, Pioneering Software, United Kingdom
//
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//------------------------------------------------------------------------------

extension Sequence where Iterator.Element == Bool {

  /// - returns: True if all true, i.e. the sequence contains no false. This
  ///   includes empty sequences because they also contain no false.
  public var all: Bool {
    return !contains(false)
  }

  /// - returns: True if at least one element is true. False if there is no true
  ///   element, which includes entirely false sets of elements and empty
  ///   sequences of elements; hence `[].any` answers false.
  public var any: Bool {
    return contains(true)
  }

}