Code review comment for lp:~raof/mir/the-least-dirty-thing

> Although I recommend against int32_t for a few reasons. "int" is better
> because:
> * On any modern platform "int" is already >= 32 bits
> * On some 64-bit platforms "int" is 64-bit and it's more efficient to use
> that native word size than forcing 32-bits.
> * int32_t increases coupling to yet another header.

No since it involves protobuf (https://developers.google.com/protocol-buffers/docs/proto#scalar)
The type should match the type assigned in protobuf or in the very least specifically converted from int32_t to whatever internal type you use. The last thing we need is a subtle type conversion issue.