Person.m

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


@interface Person : NSObject
@end
@implementation Person
@end

@interface Person(dynamicProperties)
@end
@implementation Person(dynamicProperties)

    static id propertyIMP(id self, SEL _cmd) {
        return [[[NSThread currentThread] threadDictionary] valueForKey:NSStringFromSelector(_cmd)];
    }
    
    static void setPropertyIMP(id self, SEL _cmd, id aValue) {
        
        id value = [aValue copy];
        NSMutableString *key = [NSStringFromSelector(_cmd) mutableCopy];
      
        [key deleteCharactersInRange:NSMakeRange(0, 3)];
        [key deleteCharactersInRange:NSMakeRange([key length] - 1, 1)];
        NSString *firstChar = [key substringToIndex:1];
        [key replaceCharactersInRange:NSMakeRange(0, 1) withString:[firstChar lowercaseString]];
      
        [[[NSThread currentThread] threadDictionary] setValue:value forKey:key];
    }

    + (BOOL)resolveInstanceMethod:(SEL)aSEL {
        if ([NSStringFromSelector(aSEL) hasPrefix:@"set"]) {
            class_addMethod([self class], aSEL, (IMP)setPropertyIMP, "v@:@");
        } else {
            class_addMethod([self class], aSEL,(IMP)propertyIMP, "@@:");
        }
        return YES;
    }

@end


int main(int argc, char *argv[]) {
    @autoreleasepool {
        Person *p = [Person new];
        [p performSelector:@selector(setName:) withObject:@"Jon"];
        NSLog(@"%@",[p performSelector:@selector(name)]);
    }
}