Kevin Gozali 47bfbbb1d3 iOS: introduce RCT_EXPORT_SYNCHRONOUS_TYPED_METHOD() macro to provide the return type of a sync method
Summary:
This provides a way to customize the return type of a sync exported method, instead of just using `id`.

```
RCT_EXPORT_SYNCHRONOUS_TYPED_METHOD(NSString *, sync1:(NSString *)x)
{
  return @"hello";
}
```

The return type needs to be a sub type of `id` - so scalars like `double` won't work (the bridge will crash).

Differential Revision: D6068884

fbshipit-source-id: 43a98141f1d0aef335aa0b33a24219f8e574e58b
2017-10-17 06:15:13 -07:00
..