[Boost-bugs] [Boost C++ Libraries] #5810: BOOST_STATIC_ASSERT requires unnecessary parentheses

Subject: [Boost-bugs] [Boost C++ Libraries] #5810: BOOST_STATIC_ASSERT requires unnecessary parentheses
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-08-24 12:01:49

#5810: BOOST_STATIC_ASSERT requires unnecessary parentheses
------------------------------+---------------------------------------------
 Reporter:  tsoae@…           |       Owner:  johnmaddock  
     Type:  Feature Requests  |      Status:  new          
Milestone:  To Be Determined  |   Component:  static_assert
  Version:  Boost 1.47.0      |    Severity:  Cosmetic     
 Keywords:                    |  
------------------------------+---------------------------------------------
 In Boost 1.47.0 the BOOST_STATIC_ASSERT macro is defined as having one
 parameter. When the argument contains comma-separated template arguments,
 we (sometimes) have to use additional parentheses:

     BOOST_STATIC_ASSERT(is_base_of<B, D>::value); /* error: two arguments
 passed */

     BOOST_STATIC_ASSERT((is_base_of<B, D>::value)); /* OK */

 Today many C++ compilers support variadic macros, so for such compilers
 BOOST_STATIC_ASSERT might be defined like this:

     #ifndef BOOST_NO_STATIC_ASSERT

     #   define BOOST_STATIC_ASSERT(...)               \
             static_assert((__VA_ARGS__), #__VA_ARGS__)
     #else
         ....

 and BOOST_STATIC_ASSERT(is_base_of<B, D>::value) might be correct. Are
 there any problems with such definition?

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/5810>
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