Re: Why are Ada compilers difficult to write ?

["Dan'l Miller" <optikos@verizon.net>]

On Wednesday, June 27, 2018 at 9:19:22 AM UTC-5, Olivier Henley wrote:
> > Ummmm, apparently you are stuck in 1992 or something.  C++ ain't your father's Oldsmobile anymore,
> > to paraphrase the old television commercials.  Time marched onward in C++, as shown in the timeline
> > at the URL below.  Threads-of-execution, sequence points, thread-local storage, condition variables,
> > multireader-uniwriter locks, threadsafe STL, atomic smart pointers, futures, latches & barriers,
> > coroutines, transactional memory, task blocks (i.e., rendezvous), plus inheriting C99's and C11's work
> > on multithreading and lack-of-aliasing.
> 
> Ummmm, apparently you are stuck in 2021 or something. C++ is your father's Oldsmobile that was
> selected for a 'Pimp My Ride' episode.
> 
> From http://clang.llvm.org/cxx_status.html
> 
> - transactional memory : No
> - task blocks are not even mentioned (N4411)
> 
> From https://gcc.gnu.org/projects/cxx-status.html
> 
> - coroutines : No
> - task blocks are not even mentioned (N4411)
> what else ... not more time to loose on that.
> 
> Do you really want me to check for Visual Studio 15/17 support for the features you mentioned?

C++ is the standardization effort's output specification-documents, especially those proposals which have been accepted or are clearly on-track to being accepted.  C++ is not some lagging snapshot of some particular compiler release.  If the undulating mass compiler feature-content is your definition of a programming language, then that programming language changes every day; job postings would need to call out specific release numbers of specific brands of compiler instead of merely saying Ada95 or Ada2012 or C++11 or C++17.

Btw, OpenWatcom is really lagging behind, but OpenWatcom is under active development.  Do we say that C++ lacks a feature until OpenWatcom catches up?  Likewise, do we say that Ada lacks a feature until every single one of its still-actively-maintained Ada compilers has the feature?

For example, clearly, C++98 is …

void LookMaNoHands()
try
  {
  ; // Your code here.
  }
catch( ... )
  {
  ; // Your code here.
  }

… even though no compiler on the planet ever implemented that standardized feature of elision of the function's outermost braces, replacing them with an outermost try-catch block.  Under your flawed logic, C++98 doesn't exist due to all compilers on the planet lacking that one feature.  And then as soon as one or all of them were to implement that old (now-deprecated) feature, poof suddenly out of the nebulous ether C++98 comes into existence ≥20 years later.