Re: [boost] C++11 Metaprogramming

Subject: Re: [boost] C++11 Metaprogramming
From: Dave Abrahams (dave_at_[hidden])
Date: 2012-04-03 14:50:36

on Tue Apr 03 2012, Howard Hinnant <howard.hinnant-AT-gmail.com> wrote:

> On Apr 3, 2012, at 1:44 PM, Dave Abrahams wrote:
>
>> 
>> on Tue Apr 03 2012, Howard Hinnant <howard.hinnant-AT-gmail.com> wrote:
>> 
>> But isn't this a better way to relieve the tedium?
>> 
>>  #define RETURNS(...)                                              \
>>  noexcept(noexcept(decltype(__VA_ARGS__)(std::move(__VA_ARGS__)))) \
>>  -> decltype(__VA_ARGS__)                                          \
>>  { return (__VA_ARGS__); }                                         \
>>  typedef int RETURNS_CAT(RETURNS_, __LINE__)
>> 
>>  #define RETURNS_CAT_0(x, y) x ## y
>>  #define RETURNS_CAT(x, y) RETURNS_CAT_0(x,y)
>> 
>> ...
>> 
>>  auto swap(B& x, B& y) RETURNS(swap(x.a,y.a), swap(x.b,y.b), ...);
>
> I hadn't seen that one before.  I guess Bjarne isn't getting rid of
> the preprocessor yet...

Nope.  I guess he's just made it all the more relevant ;-)

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com