Strange seg fault

[gedaiu]

Hi,

Can anyone help me why this code goes wrong? I get exit code 139 
with DMD 2.063


import std.stdio;



struct Test {
        string val = "";
        string[] key;
        
        /**
         * operator "=" overload
         */
        Test opAssign(string val){
                this.val = val;
                
                string[1] t;
                t = val;
                
                key ~= t;
                
                return this;
        }
        
        Test opAssign(Test val){
                this.val = val.val;
                
                key ~= val.key;
                
                return this;
        }
        
        void append(Test t) {
                val ~= t.val;
                key ~= t.key;
        };
}

void main() {
        
        Test val;
        val = "test";
        
        Test[string] data;
        Test v;
        v = "asd";
        data["test"] = v;
        
        writeln(v);
        writeln(data["test"]);
        
        data["test"].append(val);
        
        
        writeln(data["test"].key);
        writeln("done");
}

Thanks,
Bogdan