import std.digest.crc : CRC32;
auto crc32 = digest!CRC32("The quick ", "brown ", "fox jumps over the lazy dog");
assert(crc32.toHexString!(Order.decreasing) == "414FA339");
assert(crc32.toHexString!(LetterCase.lower, Order.decreasing) == "414fa339");
See toHexString