From: pbristow_at_[hidden]
Date: 2007-09-21 08:35:01
Author: pbristow
Date: 2007-09-21 08:35:01 EDT (Fri, 21 Sep 2007)
New Revision: 39444
URL: http://svn.boost.org/trac/boost/changeset/39444
Log:
Weasel to allow infinity - sometimes
Text files modified:
sandbox/math_toolkit/libs/math/doc/implementation.qbk | 10 +++++++---
1 files changed, 7 insertions(+), 3 deletions(-)
Modified: sandbox/math_toolkit/libs/math/doc/implementation.qbk
==============================================================================
--- sandbox/math_toolkit/libs/math/doc/implementation.qbk (original)
+++ sandbox/math_toolkit/libs/math/doc/implementation.qbk 2007-09-21 08:35:01 EDT (Fri, 21 Sep 2007)
@@ -187,10 +187,10 @@
Some functions and distributions are well defined with + or - infinity as
argument(s), but after some experiments with handling infinite arguments
-as special cases, we concluded that it was more useful to forbid this,
-and instead to return the result of __domain_error.
+as special cases, we concluded that it was generally more useful to forbid this,
+and instead to return the result of __domain_error.
-Handling infinity as special cases was additionally complicated
+Handling infinity as special cases is additionally complicated
because, unlike built-in types on most - but not all - platforms,
not all User-Defined Types are
specialized to provide `std::numeric_limits<RealType>::infinity()`
@@ -202,6 +202,10 @@
The code also became much more complicated, more error-prone,
much more work to test, and much less readable.
+However in a few cases, for example normal, where we felt it obvious,
+we have permitted argument(s) to be infinity,
+provided infinity is implemented for the realType on that implementation.
+
Overflow, underflow, denorm can be handled using __error_policy.
We have also tried to catch boundary cases where the mathematical specification