FFI-safe types for writing and transcribing C APIs.
&CStr and CString are not FFI safe.
extern "C"
&SeaStr and [SeaString] are FFI-safe equivalents.
extern "C"
They use the non-null niche which is filled by [Option::None].
/** may return null */
char *;
extern "C"
assert_eq!;
[SeaBox] is an additional owned pointer type, with a pluggable [Allocator].