main.mm

//
//  main.mm
//  foo2
//
//  Created by Richard Hodges on 21/09/2016.
//  Copyright © 2016 Richard Hodges. All rights reserved.
//

#include <vector>
#import <Foundation/Foundation.h>

@interface Thing : NSObject
@end

@implementation Thing


@end

extern void foo(Thing*);

int main()
{
    // declare my vector
    std::vector<__weak Thing*> myThings;
    
    // store a weak reference in it
    Thing* t = [[Thing alloc]init];
    myThings.push_back(t);
    
    // ... some time later ...
    
    for(auto weak : myThings) {
        Thing* strong = weak; // safely lock the weak pointer
        if (strong) {
            foo(strong);
            // use the locked pointer
        }
    }

    t = nullptr;

    for(auto weak : myThings) {
        Thing* strong = weak; // safely lock the weak pointer
        if (strong) {
            foo(strong);
            // use the locked pointer
        }
    }
}

void foo(Thing*p)
{
    NSLog(@"%@", [p className]);
}

// expected: one log output