garsdle

struct SizePreferenceKey: PreferenceKey {
    static var defaultValue: CGSize = .zero

    static func reduce(value: inout CGSize, nextValue: () -> CGSize) {
        value = nextValue()
    }
}

struct RelativeSizeModifier: ViewModifier {
    let percentWidth: CGFloat

ollieatkinson

import Darwin
import Foundation
import UIKit

// https://github.com/xybp888/iOS-SDKs/blob/master/iPhoneOS17.1.sdk/System/Library/PrivateFrameworks/CoreSVG.framework/CoreSVG.tbd
// https://developer.limneos.net/index.php?ios=17.1&framework=UIKitCore.framework&header=UIImage.h

@objc
class CGSVGDocument: NSObject { }

macshome

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The Wisdom of Quinn

Informative DevForum posts from everyone's favorite DTS member.

(Arranged newest to oldest)

IanKeen

struct User: Equatable {
    var firstName: String
    var lastName: String
}

@main
struct MyApp: App {
    @State var value = User(firstName: "", lastName: "")
    @State var showEdit = false

IanKeen

import Foundation

public protocol CodingStrategy {
    associatedtype Converted
    associatedtype RawValue: Codable

    static func toRaw(_ value: Converted) throws -> RawValue
    static func toValue(_ raw: RawValue) throws -> Converted
}

anandabits

/// - returns: `true` when dynamic type is `Equatable` and `==` returns `true`, otherwise `false`.
func areEquatablyEqual(_ lhs: Any, _ rhs: Any) -> Bool {
    func receiveLHS<LHS>(_ typedLHS: LHS) -> Bool {
        guard
            let rhsAsLHS = rhs as? LHS
            else { return false }
        return areEquatablyEqual(typedLHS, rhsAsLHS)
    }
    return _openExistential(lhs, do: receiveLHS)
}

IanKeen

@dynamicMemberLookup
struct Combined<A, B> {
    private let a: A
    private let b: B

    init(a: A, b: B) { (self.a, self.b) = (a, b) }

    subscript<T>(dynamicMember keyPath: KeyPath<A, T>) -> T {
        return a[keyPath: keyPath]
    }

IanKeen

class DictionaryEncoder {
    init() { }
    
    func encode(_ value: Encodable) throws -> [String: Any] {
        let encoder = _Encoder(codingPath: [])
        try value.encode(to: encoder)
        
        guard let result = encoder.value as? [String: Any] else {
            throw EncodingError.invalidValue(encoder.value as Any, .init(codingPath: [], debugDescription: "Invalid root container"))
        }

chriseidhof

import Foundation
import NIO
import NIOHTTP1

// Inspired/parts copied from http://www.alwaysrightinstitute.com/microexpress-nio/

final class HelloHandler: ChannelInboundHandler {
    typealias InboundIn = HTTPServerRequestPart
    
    func channelRead(ctx: ChannelHandlerContext, data: NIOAny) {

tclementdev

libdispatch efficiency tips

The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).

My take-aways are:

• You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.

• Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse