On 1 March 2012 23:34, Jeffrey Lee Hellrung, Jr. <jeffrey.hellrung@gmail.com> wrote:
I think the important distinction is
"BOOST_NO_INITIALIZER_LISTS is probably useless as it only indicates compiler support and initializer lists can't really be used without the header."
I wasn't sure whether initializer lists required a header, so I agree with Daniel that it's probably redundant.
I was wrong, C++11 added other uses which don't require the header. Although I don't think portable code would ever need to take advantage of that. The situation with the visual c++ 10 beta was that initializer lists weren't supported, but the header was present. In that case BOOST_NO_INITIALIZER_LISTS would be defined, but BOOST_NO_0X_HDR_INITIALIZER_LISTS would not. A compiled library might still want to define methods which take initializer lists so that they can be used when linking with a different compiler that does support them. If you look at unordered, it now uses BOOST_NO_0X_HDR_INITIALIZER_LISTS in the headers (they support std::initializer_list but don't ever create one), but BOOST_NO_INITIALIZER_LISTS for test cases that actually use an initializer list. But.... it looks like including the header in Visual C++ 10 was actually a mistake: http://connect.microsoft.com/VisualStudio/feedback/details/533464/the-initia... It's also confusing having the two macros, very easy to get wrong, and the potential use cases are pretty dubious.