Chris Biscardi: [0:00] In macros3, we have another scoping issue where we have to make this compile without moving the macro out of the module. Note that we use the macro in the main function while the macro is defined in the macros module.
[0:11] As we've seen before, you might think that putting pub in front of macro_rules would fix this problem, but it does not. However, using pub in front of macro_rules points us to the actual solution.
[0:21] The Rust compiler suggests using the macro_export. If we follow what the Rust compiler tells us and put macro_export on top of our macro_rules, our macro is now available in scope.