typedef a struct before it's declared

Question

I\'m not a beginner, I\'m very familiar with the following idiom:

typedef struct Foo_ Foo;// I know typedef struct Foo Foo is fine, I\'m just trying to make          


        

Answer 1

It's called forward declaring. The forward declaration allows you to use its name in context where an incomplete type is allowed.

The compiler will "see" the typedef tag, and store it away until the type is found, so as long as you have the type declared in there after the typedef, but before any usage, it's fine.