SwiftCore

Posted on

Bool

占一个字节，有效位只有一个bit

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@frozen
public struct Bool {
  @usableFromInline
  internal var _value: Builtin.Int1

  /// Creates an instance initialized to `false`.
  ///
  /// Do not call this initializer directly. Instead, use the Boolean literal
  /// `false` to create a new `Bool` instance.
  @_transparent
  public init() {
    let zero: Int8 = 0
    self._value = Builtin.trunc_Int8_Int1(zero._value)
  }

  @usableFromInline @_transparent
  internal init(_ v: Builtin.Int1) { self._value = v }
  
  /// Creates an instance equal to the given Boolean value.
  ///
  /// - Parameter value: The Boolean value to copy.
  @inlinable
  public init(_ value: Bool) {
    self = value
  }
  ...