On December 14, 2012 10:52:29 AM Marshall Clow wrote:
On Dec 14, 2012, at 8:38 AM, Steve M. Robbins <steve@sumost.ca> wrote:
On Thu, Dec 13, 2012 at 07:53:06AM -0800, Marshall Clow wrote:
There are a set of macros in Boost.config that describe "features that are not required by the C++ standard"
Some of these features have been incorporated into C++11.
I propose that we retire these macros, and have people use the shiny C++11 versions.
In particular: BOOST_HAS_STATIC_ASSERT should be ! BOOST_NO_CXX11_ASSERT
I'm curious why Boost is changing from a positive macro "system has feature X" to a negative one. Of the two options:
#ifdef BOOST_HAS_X ...
or
#ifndef BOOST_NO_X ...
I personally find the former much easier to read and the latter double-negative version awkward enough to be error prone. Am I alone in this opinion?
Here's my understanding, based on reading the docs at: http://www.boost.org/doc/libs/1_52_0/libs/config/doc/html/boost_config/boo st_macro_reference.html
For things that are in the standard, we note their absence. For example: BOOST_NO_STDC_NAMESPACE and BOOST_NO_CXX11_RVALUE_REFERENCES
For optional (extra?) language/library features, we note their presence BOOST_HAS_TR1 or BOOST_HAS_SGI_TYPE_TRAITS
Thanks. This proves that the choice is deliberate. However, it doesn't answer whether using the double-negative is a good idea. Why not use BOOST_STDC_NAMESPACE and BOOST_CXX11_RVALUE_REFERENCES instead? -Steve