assert(fastLog10(1) == 0); assert(fastLog10(9) == 0); assert(fastLog10(11) == 1); assert(fastLog10(99) == 1); assert(fastLog10(111) == 2); assert(fastLog10(999) == 2); assert(fastLog10(1_111) == 3); assert(fastLog10(9_999) == 3); assert(fastLog10(11_111) == 4); assert(fastLog10(99_999) == 4); assert(fastLog10(999_999_999) == 8); assert(fastLog10(1_000_000_000) == 9); assert(fastLog10(uint.max) == 9);