定義上変な感じは特にないので、アンダースコア付きのidentifierが自動的に隠されたりしてるのかな
public protocol ViewModifier { static func _makeView(modifier: SwiftUI._GraphValue<Self>, inputs: SwiftUI._ViewInputs, body: @escaping (SwiftUI._Graph, SwiftUI._ViewInputs) -> SwiftUI._ViewOutputs) -> SwiftUI._ViewOutputs static func _makeViewList(modifier: SwiftUI._GraphValue<Self>, inputs: SwiftUI._ViewListInputs, body: @escaping (SwiftUI._Graph, SwiftUI._ViewListInputs) -> SwiftUI._ViewListOutputs) -> SwiftUI._ViewListOutputs @available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *) static func _viewListCount(inputs: SwiftUI._ViewListCountInputs, body: (SwiftUI._ViewListCountInputs) -> Swift.Int?) -> Swift.Int? associatedtype Body : SwiftUI.View @SwiftUI.ViewBuilder @_Concurrency.MainActor(unsafe) func body(content: Self.Content) -> Self.Body typealias Content = SwiftUI._ViewModifier_Content<Self> } @available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, *) public struct _ViewModifier_Content<Modifier> : SwiftUI.View where Modifier : SwiftUI.ViewModifier { public static func _makeView(view: SwiftUI._GraphValue<SwiftUI._ViewModifier_Content<Modifier>>, inputs: SwiftUI._ViewInputs) -> SwiftUI._ViewOutputs public static func _makeViewList(view: SwiftUI._GraphValue<SwiftUI._ViewModifier_Content<Modifier>>, inputs: SwiftUI._ViewListInputs) -> SwiftUI._ViewListOutputs @available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *) public static func _viewListCount(inputs: SwiftUI._ViewListCountInputs, body: (SwiftUI._ViewListCountInputs) -> Swift.Int?) -> Swift.Int? @available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *) @_alwaysEmitIntoClient public static func _viewListCount(inputs: SwiftUI._ViewListCountInputs) -> Swift.Int? { _viewListCount(inputs: inputs) { _ in nil } } public typealias Body = Swift.Never }