Query.cs

void Main()
{
	DumpAnonymousType(new { i = 42, j = 13 });
	DumpAnonymousType((i: 42, j: 13));
}

void DumpAnonymousType(object o)
{
	var properties = o.GetType().GetProperties();
	
	if (!properties.Any())
		throw new InvalidOperationException();
	
	string.Join("; ", properties.Select(p => $"{p.Name}: {p.GetValue(o)}")).Dump();
}