import std.stdio;

struct JSONValue {
    union {
        string              str;
        long                integer;
        real                floating;
        JSONValue[string]   object;
        JSONValue[]         array;
    }
    
    int type;
}

void main()
{
    JSONValue foo;
    foo.str = "a";  // remove to avoid access violation
    
    JSONValue bar;
    bar.object["foo"] = foo;
    
    writeln(bar.object["foo"]);  // object.Error: Access Violation
}

This is taken from std.json, which suffers from these segfaults when you try to print out the 'object' field. Using `foreach (key, val)` works fine though.