Overloading struct members (or cast?)

[Ali Çehreli via Digitalmars-d-learn]

On 11/18/2014 07:32 AM, Wsdes wrote:

 >             Error: need 'this' for 'string' of type 'const(char*)'

Reduced:

struct S
{
     union Value
     {
         const char* myString;
     }
}

void main()
{
     auto s = S();
     auto mine = s.Value.myString;    // ERROR
}

You may be thinking that Value introduces a name scope so that you can 
reference its myString by Value.myString.

You have two options:


a) Remove Value so that it is an anonymous union. myString becomes a 
direct member of S:

struct S
{
     union    // <-- Anonymous
     {
         const char* myString;
     }
}

void main()
{
     auto s = S();
     auto mine = s.myString;    // <-- No more Value
}


b) Make S have an actual member of type Value:

struct S
{
     union Value
     {
         const char* myString;
     }

     Value value;    // <-- Added
}

void main()
{
     auto s = S();
     auto mine = s.value.myString;    // <-- Note lower initial
}

Ali