I read a high quality post titled Rust ownership, the hard way. I
learned quite a bit going through it, like the meaning of
#[derive(Clone, Copy)], which I see a lot but never knew what it
meant. I also learned that there are 7 ways to introduce a variable
binding (taking foo as the name of that binding):
let foo ...
for foo in ... (for loop)
foo => ... (match block)
if let foo = ... (if block)
while let foo = ... (while loop)
fn func(foo: ... (function argument)
| foo | ... (closure argument)