ARC vs none ARC

as.md

ARC:

SomeHacks.h

@interface SomeHacks : NSObject

@end

SomeHacks.m

@implementation SomeHacks

-(void) foo {
    NSLog(@"\n\nFOOOOOOOO\n\n");
}

@end

Caller:

SomeHacks* hacks = [[SomeHacks alloc] init];

[hacks foo];

COMPILE ERROR: ARC Semantic Issue: No visible @interface for 'SomeHacks' declares the selector 'foo'

gistfile1.md

No ARC:

SomeHacks.h

@interface SomeHacks : NSObject

@end

SomeHacks.m

@implementation SomeHacks

-(void) foo {
    NSLog(@"\n\nFOOOOOOOO\n\n");
}

@end

Caller:

SomeHacks* hacks = [[SomeHacks alloc] init];

[hacks foo];

WARNING this code compiles and invokes the 'foo' - Generates (expected) warning "Instance method '-foo' not found (return type defaults to 'id')"