[Boost-bugs] [Boost C++ Libraries] #9013: Create enum to make sign result more readable.

Subject: [Boost-bugs] [Boost C++ Libraries] #9013: Create enum to make sign result more readable.
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-08-18 16:28:55

#9013: Create enum to make sign result more readable.
-----------------------------------------------+-------------------------
 Reporter:  Joaquim Duran Comas <jduran.gm@…>  |      Owner:  johnmaddock
     Type:  Feature Requests                   |     Status:  new
Milestone:  To Be Determined                   |  Component:  math
  Version:  Boost 1.54.0                       |   Severity:  Cosmetic
 Keywords:  math, sign, enum type              |
-----------------------------------------------+-------------------------
 The function 'sign' return 1, 0 or -1 depending on the signal of the z,
 but comparing the result with -1, 0 or 1 constants could make the source
 code bad readable specially for people that doesn't know what the 'sign'
 function return.

 {{{
 if (math::sign(value) == -1){
 ....
 }
 }}}

 I propose to create an enumerate type to test the result of the function
 with a constant, to create a more readable code. The compatibility with
 the previous implementation of the function is not broken.

 Suggested implementation of code:

 {{{
 enum Sign
 {
         SIGN_NEGATIVE = -1,
         SIGN_ZERO = 0,
         SIGN_POSITIVE = 1
 }

 template <class T>
 inline Sign sign BOOST_NO_MACRO_EXPAND(const T& z)
 {
    return (z == 0) ? SIGN_ZERO : (boost::math::signbit)(z) ? SIGN_NEGATIVE
 : SIGN_POSITIVE;
 }
 }}}

 The previous example comparison could be write as:

 {{{
 if (math::sign(value) == math::SIGN_NEGATIVE){
 ....
 }
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/9013>
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