std.conv - custom string to struct conversion ?

[Douglas Petterson]

Is there a way to convert a string to a struct, similarly to the 
conversion of a struct to a custom string representation ?

The following code works fine when using format("%s",C) or 
to!string(C):

    struct sCustomConv
    {
        string toString()
        {
            return "My custom representation";
        }
    }

    sCustomConv C;
    string MyBackup = to!string(C);

But I can't find which class operator must be overloaded (or more 
simply how-to) to make this possible:

    C = to!sCustomConv(MyBackup);

Thx.