Support Unpacking of std.variant.VariantN

[nordlow]

How can I extend msgpack and submit a PR to support unpacking of std.variant.VariantN?

import std.variant: Algebraic;
import std.conv;
import std.stdio;
import std.traits;
import std.array: array;

import msgpack;

void main()
{
    auto v = Algebraic!(long, double)(5.to!long);

    assert(v == 5.to!long);
    assert(v == 5.to!double);
    assert(*(v.peek!long) == 5);
    assert(v.peek!double is null);

    writeln(`typeof(v.peek!double).stringof: `, typeof(v.peek!double).stringof);
    writeln(`typeof(v).stringof: `, typeof(v).stringof);
    writeln(`string.sizeof: `, string.sizeof);
    writeln(`v.sizeof: `, v.sizeof);
    writeln(`v.AllowedTypes.stringof: `, v.AllowedTypes.stringof);

    auto vp = v.pack;

    writeln(`typeof(v).stringof: `, typeof(v.pack).stringof);
    writeln(`typeof(vp.unpack).stringof: `, typeof(vp.unpack).stringof);

    writeln("v.pack.array: ", vp.array);

    auto vr = vp.unpack;

    assert(vp == vr);
}

compiles but deserialization errors at run-time as

typeof(v.peek!double).stringof: double*
typeof(v).stringof: VariantN!(8LU, long, double)
string.sizeof: 16
v.sizeof: 16
v.AllowedTypes.stringof: (long, double)
v.pack.array: [146, 168, 5, 0, 0, 0, 0, 0, 0, 0]
msgpack.UnpackException@/home/per/Work/justd/msgpack.d(305): Deserialization failure

Why does msgpack allow serialization but not deserialization?

Notice that VariantN is a struct type.

[repeatedly]

Why does msgpack allow serialization but not deserialization?

msgpack-d tries to pack Variant as normal struct. There is no check.
Maybe serialized result doesn't fit for deserialization because Variant uses union.
I will check it later.

[nordlow]

Thanks.