On the evolution of programming style: How far C++ has moved from its C roots

Re:On the evolution of programming style: How far C++ has mo... by alexk7 on Monday March 26, 2012 @01:46PM (#3757777)

This is even more C++11-ish: (Not tested, my compiler at work is not C++11 compliant.)

    constexpr tuple<double, double> Roots(double a, double b, double c)
    {
        return (a == 0.0) ? throw invalid_argument("a has value 0.0!") :
            tuple<double, double>{
                (-b + (sqrt((b * b) - 4 * a * c))) / 2*a,
                (-b - (sqrt((b * b) - 4 * a * c))) / 2*a
            };
    }

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Re:On the evolution of programming style: How far C++ has mo... by jsnell on Monday March 26, 2012 @02:51PM (#3758090)

That's just horrible. The readability of the function has been totally destroyed by conditional operator. What's the imaginary C++11-ish benefit?

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Re:On the evolution of programming style: How far C++ has mo... by alexk7 on Monday March 26, 2012 @04:36PM (#3758518)

With constexpr, if the parameters are constants, the whole computation can happen at compile-time. The line is somewhat harder to read for people not used to functional programming, but unfortunately, constexpr functions are required to have a single expression.

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Re:On the evolution of programming style: How far C++ has mo... by hythloday on Monday March 26, 2012 @03:41PM (#3758304)

  return /* ... */ throw invalid_argument("");

really valid C++11?

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Re:On the evolution of programming style: How far C++ has mo... by alexk7 on Monday March 26, 2012 @04:38PM (#3758530)

"The rules for conditional operator are quite sophisticated and one of them says that if one of the sub-expressions is a throw expression, the type of the entire conditional operator is that of the other sub-expression." [1]

[1] http://akrzemi1.wordpress.com/2011/05/06/compile-time-comput...

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Re:On the evolution of programming style: How far C++ has mo... by hythloday on Monday March 26, 2012 @07:59PM (#3759245)

Thanks for both your and pdw's explanations...the lovely thing about C++ is that there's always something new to learn. ;)

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Re:On the evolution of programming style: How far C++ has mo... by pdw on Monday March 26, 2012 @05:11PM (#3758666)

It's valid in all versions of C++, I believe. It's usually motivated with a chained ternary operator:

  return a == ALPHA ? x :
         a == BETA ? y :
         a == GAMMA ? z :
         throw ...;

Although that's not a style I'd recommend.

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