Macro check_same_layout 

macro_rules! check_same_layout {
    () => { ... };
    (
        $type_name1:ty = $type_name2:ty { $($($field1:ident).+ =>
        $($field2:ident).+),* $(,)? } $($token:tt)*
    ) => { ... };
}

Ensure 2 different types have the same layout.

Usage:

check_same_layout! {
    Type1 = Type2 {
        type1_field1 => type2_field1,
        type1_field2 => type2_field2,
        ...
    }
}