[boost] Re: random_test, GCC and minmax macros

From: Eric Niebler (eric_at_[hidden])
Date: 2004-08-16 10:00:51

Michael Stevens wrote:
> The 'random_test' has been failing on GCC-3.3 for quite some time...
> 
> Looking a bit deeper the failure was rather nasty resulting in a infinite 
> recursion. A lot of waist CPU and memory usage when running regression tests!
> 
> The problem is GCC-3.3 specific and cause by a compiler bug. It was 
> inadvertently introduced by Eric minmax workarounds.
> 
> Specificly the 'max' member  functions of class ruetti_gen in 
> "random_test.cpp" and class rand48 in "linear_congruential.hpp" were defined:
> 
>      result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const
>      { return (std::numeric_limits<result_type>::max)(); }
> 
> Amazingly these are recursing, with max calling itseld rather then the correct 
> max from numeric_limits! I have committed a fix which uses a different syntax 
> thus:
> 
>      result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const
>     { return std::numeric_limits<result_type>::max
>                  BOOST_PREVENT_MACRO_SUBSTITUTION (); }
> 
> Eric, is this correct from a minmax macro point of view?

Yes, this is fine. But I'm amazed the compiler got it wrong the first 
time. (/me scratches his head and looks perplexed.)

-- 
Eric Niebler
Boost Consulting
www.boost-consulting.com