These are implementation defined but share identical values in at least musl and glibc:
pub const LC = enum(c_int)
pub const LC = enum(c_int) {
CTYPE = 0,
NUMERIC = 1,
TIME = 2,
COLLATE = 3,
MONETARY = 4,
MESSAGES = 5,
ALL = 6,
PAPER = 7,
NAME = 8,
ADDRESS = 9,
TELEPHONE = 10,
MEASUREMENT = 11,
IDENTIFICATION = 12,
_,
}