BitArray/BitFields - Reworking with templates

[Era Scarecrow]

On Sunday, 29 July 2012 at 12:39:13 UTC, Era Scarecrow wrote:
>  But having them statically separated by name/type seems much 
> more likely to be safer in the long run with reliable results.

  A question regarding templates. A template with different 
parameters is completely incompatible correct? So...

struct X(T) {
}

alias X!bool XB;
alias X!int XI;

void func(XB xb) {

}

func(XB()); //works
func(XI()); //should fail to compile

Same if it was built differently? so...

template X(bool something) //'bool something' should be 
statically checkable
   struct XY {
     static if (something) {
       //conditional functions or code
     }
     XY makeX(){
       //XY type is only currently formed template version correct?
       return XY();
     }
   }
}

//against above func, with these two...
alias X!(false).XY XB;
alias X!(true).XY XI;

Course if there's a way to avoid asking about the inner XY, I 
wonder how I would do that.


  Now if all that is correct, say I want to make two functions 
that both use X, but are not compatible, but template functions 
will allow it. So...

void tempFunc(T, U)(T t, U u)
if(
   //What do i enter to check they are both template X or struct 
XY? As signatures will be different...
)
body{
   //now acts as a middle-man to be compatible for said operation
}


  Finally, I came across an anomaly and may just be a bug. What 
about a postblits?


T func2(T)(T x) @safe pure {
   return T();
}

struct XY {
   this(this) @safe pure {} //safe pure added so func can call it
   void func(XY x) @safe pure {
     XY y = x; //postblits called on all three lines
     func2(x);
     func2(y);
   }
}

template X(bool something) {
struct XY {
     this(this) @safe pure {}
     void func(XY x) @safe pure {
       XY y = x; //Error: see below
       func2(x);
       func2(y);
     }
   }
}

alias X!(true).XY Xtrue;

pure function 'func' cannot call impure function '__cpctor'
safe function 'func' cannot call system function '__cpctor'