The D2 language specification does not fully define the conversation performed by cast() operation, http://d-programming-language.org/expression.html#CastExpression.

For example cast() between basic data types of different sizes and signess is not described.

e.g:

  int a;
  byte b = cast(int)a;

Casting pointers to basic data types is also not described.

I think the specification should define when the value is truncated, sign extended or copied bit-by-bit, etc.

Maybe a reference to relevant C language specification would solve this issue.