[random] fix assert in uniform_real.hpp
diff -r 5fcada374f41 boost/random/uniform_real.hpp --- a/boost/random/uniform_real.hpp Thu May 10 08:59:36 2007 -0400 +++ b/boost/random/uniform_real.hpp Fri May 11 11:12:44 2007 -0400 @@ -40,7 +40,7 @@ public: #ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS BOOST_STATIC_ASSERT(!std::numeric_limits<RealType>::is_integer); #endif - assert(min_arg < max_arg); + assert(min_arg <= max_arg); } // compiler-generated copy ctor and assignment operator are fine
On 11 May 2007, at 23:13, Neal Becker wrote:
diff -r 5fcada374f41 boost/random/uniform_real.hpp --- a/boost/random/uniform_real.hpp Thu May 10 08:59:36 2007 -0400 +++ b/boost/random/uniform_real.hpp Fri May 11 11:12:44 2007 -0400 @@ -40,7 +40,7 @@ public: #ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS BOOST_STATIC_ASSERT(!std::numeric_limits<RealType>::is_integer); #endif - assert(min_arg < max_arg); + assert(min_arg <= max_arg); }
// compiler-generated copy ctor and assignment operator are fine
This does not make sense to me. uniform_real should create numbers u that are min_arg <= u < maxarg Thus choosing minarg == maxarg does not make sense since the set of possible values would be empty. Matthias
Matthias Troyer wrote:
On 11 May 2007, at 23:13, Neal Becker wrote:
diff -r 5fcada374f41 boost/random/uniform_real.hpp --- a/boost/random/uniform_real.hpp Thu May 10 08:59:36 2007 -0400 +++ b/boost/random/uniform_real.hpp Fri May 11 11:12:44 2007 -0400 @@ -40,7 +40,7 @@ public: #ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS BOOST_STATIC_ASSERT(!std::numeric_limits<RealType>::is_integer); #endif - assert(min_arg < max_arg); + assert(min_arg <= max_arg); }
// compiler-generated copy ctor and assignment operator are fine
This does not make sense to me. uniform_real should create numbers u that are
min_arg <= u < maxarg
Thus choosing minarg == maxarg does not make sense since the set of possible values would be empty.
It's a valid limiting case. Here's the use case: Your program has a random number generator. The range is set by command line argument. For test purposes, you set the range to be infinitesimal. As it is now, you get the assertion failure. There is no good reason for this to fail, AFAICT. Allowing it is useful and harmless.
On 13 May 2007, at 10:45, Neal Becker wrote:
Matthias Troyer wrote:
On 11 May 2007, at 23:13, Neal Becker wrote:
diff -r 5fcada374f41 boost/random/uniform_real.hpp --- a/boost/random/uniform_real.hpp Thu May 10 08:59:36 2007 -0400 +++ b/boost/random/uniform_real.hpp Fri May 11 11:12:44 2007 -0400 @@ -40,7 +40,7 @@ public: #ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS BOOST_STATIC_ASSERT(! std::numeric_limits<RealType>::is_integer); #endif - assert(min_arg < max_arg); + assert(min_arg <= max_arg); }
// compiler-generated copy ctor and assignment operator are fine
This does not make sense to me. uniform_real should create numbers u that are
min_arg <= u < maxarg
Thus choosing minarg == maxarg does not make sense since the set of possible values would be empty.
It's a valid limiting case.
Here's the use case:
Your program has a random number generator. The range is set by command line argument. For test purposes, you set the range to be infinitesimal. As it is now, you get the assertion failure. There is no good reason for this to fail, AFAICT. Allowing it is useful and harmless.
Sorry, the range is not infinitesimal but is empty. What value should the generator return when minarg == maxarg? In that case there is no legal value. Should the generator check and throw when invoked? Matthias
Matthias Troyer wrote:
On 13 May 2007, at 10:45, Neal Becker wrote:
Matthias Troyer wrote:
On 11 May 2007, at 23:13, Neal Becker wrote:
diff -r 5fcada374f41 boost/random/uniform_real.hpp --- a/boost/random/uniform_real.hpp Thu May 10 08:59:36 2007 -0400 +++ b/boost/random/uniform_real.hpp Fri May 11 11:12:44 2007 -0400 @@ -40,7 +40,7 @@ public: #ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS BOOST_STATIC_ASSERT(! std::numeric_limits<RealType>::is_integer); #endif - assert(min_arg < max_arg); + assert(min_arg <= max_arg); }
// compiler-generated copy ctor and assignment operator are fine
This does not make sense to me. uniform_real should create numbers u that are
min_arg <= u < maxarg
Thus choosing minarg == maxarg does not make sense since the set of possible values would be empty.
It's a valid limiting case.
Here's the use case:
Your program has a random number generator. The range is set by command line argument. For test purposes, you set the range to be infinitesimal. As it is now, you get the assertion failure. There is no good reason for this to fail, AFAICT. Allowing it is useful and harmless.
Sorry, the range is not infinitesimal but is empty. What value should the generator return when minarg == maxarg? In that case there is no legal value. Should the generator check and throw when invoked?
Agreed, I forgot that range was [min..max)
participants (2)
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Matthias Troyer -
Neal Becker