String/StringView/UUIDValueに三方比較演算子を実装

[tetsurom]

Part of #658

String

assert(U"a"_s == U"a"_s);
assert(U"b"_s != U"a"_s);
assert(U"b"_s >  U"a"_s);
assert(U"b"_s >= U"a"_s);
assert(U"b"_s <  U"c"_s);
assert(U"b"_s <= U"c"_s);

assert(U"a" == U"a"_s);
assert(U"b" != U"a"_s);
assert(U"b" >  U"a"_s);
assert(U"b" >= U"a"_s);
assert(U"b" <  U"c"_s);
assert(U"b" <= U"c"_s);

assert(U"a"_s == U"a");
assert(U"b"_s != U"a");
assert(U"b"_s >  U"a");
assert(U"b"_s >= U"a");
assert(U"b"_s <  U"c");
assert(U"b"_s <= U"c");

StringView

static_assert(U"a"_sv == U"a"_sv);
static_assert(U"b"_sv != U"a"_sv);
static_assert(U"b"_sv >  U"a"_sv);
static_assert(U"b"_sv >= U"a"_sv);
static_assert(U"b"_sv <  U"c"_sv);
static_assert(U"b"_sv <= U"c"_sv);

assert(U"a"_sv == U"a"_s);
assert(U"b"_s  != U"a"_sv);
assert(U"b"_sv >  U"a");
assert(U"b"    >= U"a"_s);

UUIDValue

UUIDValue id1{ std::array<std::uint8_t, 16> { 0 } };
UUIDValue id2{ std::array<std::uint8_t, 16> { 1 } };
assert(id1 == id1);
assert(id1 != id2);
assert(id2 >  id1);
assert(id2 >= id1);
assert(id1 <  id2);
assert(id1 <= id2);

[tetsurom]

Array/Optionalは見直しが必要そうなので一度下げます。

[Reputeless]

Merged. Thank you!