On Sunday, 26 March 2017 at 15:29:02 UTC, Jonathan M Davis wrote:
Personally, I don't think that the fact that you can't use const for head-const in D is really a loss, since it's almost never what you want. Tail-const is _way_ more useful. But it is true that by making D's const fully transitive, there are variations of constness that C++ can do that D can't. immutable pretty much forces that though, and it does simplify the language.
There are quite a few things wrong with const, it's so bad phobos isn't even const-correct when it should be. In cmp() for example, if you pass a lambda that takes the parameters by reference. You will be modifying temporary values that cmp() created on the stack. These should be const, but then what if it is a pointer? It is a different situation and you don't really want const cause you are going to be modifying the correct struct (the one pointed to). It is just easier to not use const in D cause it makes your code more difficult to actually use. That's exactly what Phobos does, it ignores const for the most part because it is easier not to use it.
