Function rawlen 

pub fn rawlen<T: length>(v: T) -> number

Returns the length of the object v, which must be a table or a string, without invoking the __len metamethod.

Examples

local t = setmetatable({1, 2, 3}, { __len = function() return 42 end })
print(#t)          --> 42
print(rawlen(t))   --> 3
print(rawlen("hello"))   --> 5