logical operands on strings

[TheFlyingFiddle]

On Sunday, 12 January 2014 at 18:37:40 UTC, Erik van Velzen wrote:
> On Sunday, 12 January 2014 at 18:28:38 UTC, Meta wrote:
>>
>> It looks like your opBinary on strings is an attempt at 
>> globally overriding the XOR operator. I'm almost 100% sure 
>> this won't work in D. All operator overloads have to be part 
>> of a class or struct.
>
> How would I do that without rewriting an entire string class?

Well something like this.

struct MyString
{
    string value;
    alias value this;

    auto opBinary(string op)(string rhs) if( op == "^" )
    {
       string result;
       foreach(i; 0 .. min(value.length, rhs.length))
           result ~= value[i] ^ rhs[i];
       return MyString(result);
    }
}

auto mstr(string s)
{
    return MyString(s);
}

auto s   = "Hello";
auto s2  = "World";


auto res = s.mstr ^ s2;
or
string res = s.mstr ^ s2; //If you want the result to be a string.

While this works it's not that much better then the simple:

auto s = "Hello";
auto s2 = "World";
auto res = s.xor(s2);

> It seems I can't even inherit from string.

In D a string is not a class its just an immutable array (slice) 
of char.
alias string = immutable(char[]);