swift-mirror/stdlib/public/Darwin/Foundation/NSValue.swift.gyb

//===--- NSValue.swift - Bridging things in NSValue -----------*- 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
//
//===----------------------------------------------------------------------===//

%{
from gyb_foundation_support import ObjectiveCBridgeableImplementationForNSValue
}%

import CoreGraphics

${ ObjectiveCBridgeableImplementationForNSValue("NSRange") }
${ ObjectiveCBridgeableImplementationForNSValue("CGRect") }
${ ObjectiveCBridgeableImplementationForNSValue("CGPoint") }
${ ObjectiveCBridgeableImplementationForNSValue("CGVector") }
${ ObjectiveCBridgeableImplementationForNSValue("CGSize") }
${ ObjectiveCBridgeableImplementationForNSValue("CGAffineTransform") }

extension NSValue {
    @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
    public func value<StoredType>(of type: StoredType.Type) -> StoredType? {
        if StoredType.self is AnyObject.Type {
            let encoding = String(cString: objCType)
            // some subclasses of NSValue can return @ and the default initialized variant returns ^v for encoding
            guard encoding == "^v" || encoding == "@" else {
                return nil
            }
            return nonretainedObjectValue as? StoredType
        } else if _isPOD(StoredType.self) {
            var storedSize = 0
            var storedAlignment = 0
            NSGetSizeAndAlignment(objCType, &storedSize, &storedAlignment)
            guard MemoryLayout<StoredType>.size == storedSize && MemoryLayout<StoredType>.alignment == storedAlignment else {
                return nil
            }
            let allocated = UnsafeMutablePointer<StoredType>.allocate(capacity: 1)
            defer { allocated.deallocate() }
            getValue(allocated, size: storedSize)
            return allocated.pointee
        }
        return nil
    }
}