Do STL containers support ARC when storing Obj-C objects in Objective-C++?

Question

For example, would this leak?

static std::tuple<CGSize, NSURL *> getThumbnailURL() {
  return std::make_tuple(CGSizeMake(100, 100), [NSURL URLWithString:@"http://examples.com/image.jpg"]);
}

Answer 1

No, it wouldn't leak. That NSURL object would be managed by ARC properly.

http://clang.llvm.org/docs/AutomaticReferenceCounting.html#template-arguments

If a template argument for a template type parameter is an retainable object owner type that does not have an explicit ownership qualifier, it is adjusted to have __strong qualification.

std::tuple<CGSize, NSURL *> is the same as std::tuple<CGSize, NSURL __strong *>. Thus NSURL object will be released when the std::tuple instance is destructed.