On Sun, Oct 7, 2012 at 11:16 PM, Jonathan M Davis <[email protected]> wrote: > > While this sort of function might be useful from time to time, how often is it > actually, realistically needed? Certainly, I'd argue that it's rare enough > that having a slightly more complicated solution specifically for it makes > more > sense than adding a whole new abstraction to the standard library. >
That particular metafunction may not have a lot of usage, I agree, but I was trying to make the point that TypeTuples do not support multi-dimensions. For example, in the Boost.units library that I'm porting to D, multi-dimensional typelist are common. To solve algebraic equations of types can require matrices, and to implement a matrix you'll need a typelist of typelist. > > So, we're not adding TypeList. > Oh, I was aware that a decision had already been made. I thought it was an open issue. > While I sympathize with your desire to get some of the functionality that > TypeList provides and TypeTuple doesn't, please work with us to improve upon > TypeTuple rather than trying to add something to Phobos that does almost the > same thing as TypeTuple. In most cases, it's simply a matter of adding the > appropriate templates to gain TypeList-like functionality on top of TypeTuple > rather than adding TypeList, and we've even recently added (post-2.060) some > of those templates to std.typetuple, thereby improving what can be done with > std.typetuple. > > - Jonathan M Davis Since TypeList is out of the question, I need to figure out what to do with the units library first.
