100644 blob ea559c02e6080a54923887b5ce1101b2cee0111b	constexpr.cc
100644 blob 1e4cabf953a249d5046f3496bb39867b4e01a132	constrained.cc
100644 blob 50bbee93d80f22bfa2fc34875bf2fb1b13c1323b	moveable.cc
040000 tree 3678f49d52f8d72d74069ad42badd37a4f702a10	requirements