baseName

assert(FilePath("/etc/foo").baseName.str == "foo");
assert(DirPath("/etc/").baseName.str == "etc");
const dmd = "https://github.com/dlang/dmd/";
assert(URL(dmd).baseName.str == "dmd");
assert(FileURL(dmd).baseName.str == "dmd");
assert(DirURL(dmd).baseName.str == "dmd");