Re: [boost] [nowide] Switching to C++11 after 1.73 release

26 Mar 2020

      On Thu, 26 Mar 2020 at 13:02, Mike via Boost  wrote:
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Gesendet: Donnerstag, 26. März 2020 um 12:25 Uhr
Von: "Mateusz Loskot via Boost" 
On Thu, 26 Mar 2020 at 11:54, Alexander Grund via Boost
 wrote:
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Ok, then I have to require MSVC 2015 which is fine to me.
How would I tell the test matrix about this?
By specifying cxx11 features as required in test/Jamfile
For example:
https://github.com/boostorg/mp11/blob/develop/test/Jamfile#L15
https://github.com/boostorg/gil/blob/develop/test/Jamfile#L57-L63
The feature I require does not yet exist. I need movable std streams
which MSVC supports since 2015 but 2013 does support most (many) C++11
features already.
Listing any cxx_* features which are not supported by VS 2013
should allow to filter 2013 and let the matix skip the builds.
That seems excessively indirect. Isn't it possible to just say "if msvc, requires msvc > 14.0" ?
Certainly, a compiler-specific filtering can be scripted in Boost.Jam.

Here is a possible solution

project
  : requirements
    <conditional>@disable-old-compiler
  ;

rule disable-old-compiler ( properties * )
{
  local result ;
  if <toolset>msvc in $(properties)
  {
    # MSVC++ 12.0 (Visual Studio 2013)
    if toolset-msvc:version12.0 in $(properties)
    {
      echo ****** This MSVC++ version is too old ****** ;
      result = <build>no ;
    }
  }
  # else if for other oldies

  return $(result) ;
}

My Boost.jam fu is very limited, so there likely is a better solution.

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net