• The library has been deprecated. It is easy to require a compatible external library or, better yet, to replace its functions with appropriate bitwise operations. (Keep in mind that bit32 operates on 32-bit integers, while the bitwise operators in Lua 5.3 operate on Lua integers, which by default have 64 bits.)
• The iterator now respects metamethods and its __ipairs metamethod has been deprecated.
• The following functions were deprecated in the mathematical library: atan2, , sinh, tanh, pow, frexp, and ldexp. You can replace math.pow(x,y) with ; you can replace math.atan2 with math.atan, which now accepts one or two arguments; you can replace math.ldexp(x,exp) with x * 2.0^exp. For the other operations, you can either use an external library or implement them in Lua.
• The call collectgarbage("count") now returns only one result. (You can compute that second result from the fractional part of the first result.)