//@ Rather than giving every field a name, a struct can also be defined by just giving a sequence
//@ of types (similar to how a variant of an `enum` is defined). This is called a *tuple struct*.
//@ It is often used when constructing a *newtype*, as we do here: `ConcurrentCounter` is
//@ Rather than giving every field a name, a struct can also be defined by just giving a sequence
//@ of types (similar to how a variant of an `enum` is defined). This is called a *tuple struct*.
//@ It is often used when constructing a *newtype*, as we do here: `ConcurrentCounter` is