Unadvertised dropped MSVC 9.0 (Visual 2008) support

[jschueller]

It seems lib boost.build uses some c++11 features unavailable in vc9:

build\src\engine\sysinfo.h(41) : error C2864: 'b2::system_info::cpu_core_count_' : only static const integral data members can be initialized within a class
sysinfo.cpp(10) : fatal error C1083: Cannot open include file: 'thread': No such file or directory

This is not mentioned in the changelog:
https://www.boost.org/users/history/version_1_71_0.html

Furthermore you mention old msvc versions that are not supported anymore:

Boost's primary test compilers are: 
...
Visual C++: 7.1, 8.0, 9.0, 10.0, 11.0, 12.0, 14.0, 14.1 

Could you confirm or update if required ?

[stale]

Thank you for your contributions. Main development of B2 has moved to https://github.com/bfgroup/b2
This issue has been automatically marked as "transition" to indicate the potential for needing transition to the new B2 development project.