On 2013-12-18 03:42:38 +0000, "Kenji Hara" <k.hara.pg@gmail.com> said:

http://wiki.dlang.org/DIP49
Improved points from version 1:
- Swap meanings of 'this(this) inout' and 'this(this) const'
- Inout postblit now covers all cheap (== not rebind indirections) copies between same qualifiers

I can't help but notice that if you want class-typed members to be assignable in a "this(this) immutable" context you'll need to add tail-constness for classes in the language.