void pack_roundtrip_check <T>(BitSize bitcount)
where T : unmanaged
{
var src = Random.BitString(bitcount);
Claim.eq(bitcount, src.Length);
var x = src.ToBits();
Claim.eq(bitcount, x.Length);
var y = Bits.pack(x);
var sizeT = size <T>();
var q = Math.DivRem(bitcount, 8, out int r);
var bytes = q + (r == 0 ? 0 : 1);
Claim.eq(bytes, y.Length);
var bulk = ByteSpan.ReadValues <T>(y, out Span <byte> rem);
var merged = rem.Length != 0 ? bulk.Extend(bulk.Length + 1) : bulk;
if (merged.Length != bulk.Length)
{
merged[merged.Length - 1] = rem.TakeScalar <T>();
}
var bsOutput = merged.ToBitString().Truncate(bitcount);
Claim.eq(src, bsOutput);
Claim.eq((src & ~bsOutput).PopCount(), 0);
}
void VerifySpanBytesToValues <T>(Span <byte> src, Span <T> expect)
where T : struct
{
Claim.eq(expect, ByteSpan.ReadValues <T>(src));
}
