Re: Really in need of help with std.container.array.d

[Nordlöw]

On Tuesday, 14 October 2014 at 16:08:31 UTC, Robert burner 
Schadek wrote:
On Tuesday, 14 October 2014 at 12:51:29 UTC, Nordlöw wrote:

Could you please give me a code example? I'm not skilled 
enough in D to follow this description.

struct Range(T) {
  Array!S array;
  T opIndex(size_t i) {
     return cast(T)array[i];
  }
}

struct Array(T) {
  Range!(const(T)) opSlice() const {
     return Range!(const(T))(cast(Array!T)array, 0, length);
  }

  Range!(T) opSlice() const {
    return Range!(T)(cast(Array!T)array, 0, length);
  }
}

I tried that at

https://github.com/nordlow/phobos/commit/9daf235d7091f76cd941e29e3c167d559bf56a94

but that triggers a new interesting suite of errors

Error: mutable method 
std.container.array.Array!int.Array.__fieldPostBlit is not 
callable using a const object
array.d(252,26): Error: 
cast(inout(int))this._outer.opIndex(this._a) is not an lvalue
array.d(258,26): Error: 
cast(inout(int))this._outer.opIndex(this._b - 1LU) is not an 
lvalue
../../std/algorithm.d(2364,9): Error: cannot modify const 
expression result
array.d(276,24): Error: template instance 
std.algorithm.move!(const(int)) error instantiating
array.d(444,5):        instantiated from here: 
Range!(const(Array!int))
array.d(856,5):        instantiated from here: Array!int
array.d(299,26): Error: cast(int)this._outer.opIndex(this._a + i) 
is not an lvalue
Error: mutable method std.container.array.Array!int.Array.~this 
is not callable using a const object
array.d(325,30): Error: None of the overloads of 'opSliceAssign' 
are callable using a const object, candidates are:
array.d(512,10):        
std.container.array.Array!int.Array.opSliceAssign(int value)
array.d(519,10):        
std.container.array.Array!int.Array.opSliceAssign(int value, 
ulong i, ulong j)
array.d(331,38): Error: None of the overloads of 'opSliceAssign' 
are callable using a const object, candidates are:
array.d(512,10):        
std.container.array.Array!int.Array.opSliceAssign(int value)
array.d(519,10):        
std.container.array.Array!int.Array.opSliceAssign(int value, 
ulong i, ulong j)
array.d(304,32): Error: mutable method 
std.container.array.Array!int.Array.Range!(Array!int).Range.this 
is not callable using a const object
array.d(314,32): Error: mutable method 
std.container.array.Array!int.Array.Range!(Array!int).Range.this 
is not callable using a const object
array.d(448,5): Error: template instance 
std.container.array.Array!int.Array.Range!(Array!int) error 
instantiating
array.d(856,5):        instantiated from here: Array!int
../../std/typecons.d(3889,17): Error: template instance 
object.destroy!(Payload) error instantiating
array.d(169,26):        instantiated from here: 
RefCounted!(Payload, cast(RefCountedAutoInitialize)0)
array.d(856,5):        instantiated from here: Array!int
array.d(885,5): Error: static assert  (!true) is false

Comint exited abnormally with code 1 at Wed Oct 15 23:14:37

I'm stuck. Need help.