chriseidhof

import SwiftUI

extension CGPoint {
    static func *(lhs: Self, rhs: CGFloat) -> Self {
        .init(x: lhs.x * rhs, y: lhs.y * rhs)
    }
}

// Idea: https://www.framer.com/showcase/project/lo2Qka8jtPXrjzZaPZdB/

keith

• Compiler flag: -enforce-exclusivity=<value>
• Build setting: SWIFT_ENFORCE_EXCLUSIVE_ACCESS

Xcode 10.1 & Swift 4.2

• Compiler default for non optimized builds if you pass no argument is the same as if you passed checked
• Compiler default for optimized builds if you pass no argument is the same as if you passed unchecked

Configuration	Compiler Flag Value	Build Setting Description	Build Setting Value	Notes

SheldonWangRJT

WWDC18 Notes - Session 416 - iOS Memory Deep Dive

All session list link: Here
Session Link: Here
Demo starts @ 25:30 in the video.
Download session slides: Here

This notes is written by Sheldon after watching WWDC18 session 416. You can find me with #iOSBySheldon in Github, Youtube, Facebook, etc.

nadavrot

High-Performance Matrix Multiplication

This is a short post that explains how to write a high-performance matrix multiplication program on modern processors. In this tutorial I will use a single core of the Skylake-client CPU with AVX2, but the principles in this post also apply to other processors with different instruction sets (such as AVX512).

Intro

Matrix multiplication is a mathematical operation that defines the product of

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

kastiglione

void addMainThreadCheck(Class cls, SEL selector) {
#if DEBUG
    void *symbol = dlsym(RTLD_DEFAULT, "__main_thread_add_check_for_selector");
    if (!symbol) {
        return;
    }
    void (*addCheck)(Class, SEL) = (__typeof__(addCheck))symbol;
    addCheck(cls, selector);
#endif
}

Catfish-Man

As of iOS 11/macOS High Sierra, and only including ones in Foundation and CoreFoundation

Strings:

_NSCFString - a CFStringRef or CFMutableStringRef. This is the most common type of string object currently.
    - May have 8 bit (ASCII) or 16 bit (UTF-16) backing store
_NSCFConstantString - a compile time constant CFStringRef, like you'd get with @"foo"
    - May also be generated by dynamic string creation if matches a string in a pre-baked table of common strings called the StringROM
NSBigMutableString - an NSString backed by a CFStorage (https://github.com/opensource-apple/CF/blob/master/CFStorage.h) for faster handling of very large strings
NSCheapMutableString - a very limited NSMutableString that allows for zero-copy initialization. Used in NSFileManager for temporarily wrapping stack buffers.

mikeash

#!/bin/bash

# Exit the script immediately on error
set -e

# We'll work in /tmp
cd /tmp

# Clone mach_override unless we already have it
if [ ! -d mach_override ]; then

chriseidhof

import Foundation

// Alternatives to `Scanner` (before: `NSScanner`).


// A scanner only needs a way to peek and to move to the next token.
protocol ScannerProtocol {
    associatedtype Token: Equatable
    var peek: Token? { get }
    mutating func moveToNextToken()

myell0w

import Foundation
import UIKit


/// Used to create a layout guide that pins to the top of the keyboard
final class KeyboardLayoutGuide {

    private let notificationCenter: NotificationCenter
    private let bottomConstraint: NSLayoutConstraint