mikeash

dispatch_block_t RecursiveBlock(void (^block)(dispatch_block_t recurse))
{
    // assuming ARC, so no explicit copy
    return ^{ block(RecursiveBlock(block)); };
}

typedef void (^OneParameterBlock)(id parameter);

OneParameterBlock RecursiveBlock1(void (^block)(OneParameterBlock recurse, id parameter))
{

mikeash

import Cocoa

enum CoroutineState {
    case Fresh, Running, Blocked, Canceled, Done
}

struct CoroutineCancellation: ErrorType {}

class CoroutineImpl<InputType, YieldType> {
    let body: (yield: YieldType throws -> InputType) throws -> Void

mikeash

#import <Foundation/Foundation.h>
#import <objc/runtime.h>

class Printer {
public:
  const char *str;
  
  ~Printer() { puts(str); }
};

mikeash

func effIt<Target, Result>(_ keypath: KeyPath<Target, Result>) -> (Target) -> Result {
    return { $0[keyPath: keypath] }
}

struct Foo {
    var x: Int
    var y: Int
}

mikeash

#import <Foundation/Foundation.h>

int main(int argc, char **argv) {
  auto global = ^{ NSLog(@"Hello, world!"); };
  auto captures = ^{ NSLog(@"argc is %d", argc); };
  NSLog(@"global: %@ -  captures: %@", global, captures);
  NSLog(@"(void *)global: %p -  (void *)captures: %p", (void *)global, (void *)captures);
  
  id globalCopy = [global copy];
  id capturesCopy = [captures copy];

mikeash

func ??<T>(lhs: T?, rhs: @autoclosure () throws -> Never) rethrows -> T {
  guard let value = lhs else { try rhs() }
  return value
}

func ??<T>(lhs: T?, rhs: () throws -> Never) rethrows -> T {
  guard let value = lhs else { try rhs() }
  return value
}

mikeash

#include <dlfcn.h>
#include <stdio.h>
#include <stdlib.h>

int main() {
  Dl_info info;
  int success = dladdr(main, &info);
  if (success == 0) abort();
  printf("main is at %p and the mach-o header that contains it is at %p\n", main, info.dli_fbase);
}

mikeash

class C {}

protocol P where Self: C {
  var x: Int { get }
  var y: Int { get }
}

extension P {
  var x: Int { return 42 }
}

mikeash

// clang -fobjc-arc -framework Foundation runtime-class.m

#import <Foundation/Foundation.h>

#import <objc/runtime.h>


@interface Person : NSObject

- (id)initWithFirstName: (NSString *)firstName lastName: (NSString *)lastName age: (NSUInteger)age;

mikeash

#import <Foundation/Foundation.h>


// .h file
struct MyConstantsStruct
{
    NSString *foo;
    NSString *bar;