Core_kernel.Immediate_option_intfA non-allocating alternative to the standard Option type.
module type S_without_immediate_plain = sig ... endmodule type S_without_immediate = sig ... endmodule type S_plain = sig ... endmodule type S = sig ... endmodule type S_int63 = sig ... endmodule type S_int63_plain = sig ... endmodule type Immediate_option = sig ... end