[Bug c++/31511] /usr/include/c++/bits/cmath.tcc: no match for ternary 'operator?:' in '((__n % 2u) != 0u) ? __x : 1'

[bav dot 272304 at gmail dot com]

------- Comment #2 from bav dot 272304 at gmail dot com  2007-04-08 21:16 -------
Code example:

============================================================

#include <complex>

template<typename T> class Wrapper {
        T x_;
public:
        Wrapper () throw () : x_(0) {}
        Wrapper (const T& x) throw () : x_(x) {}
        Wrapper operator* (const Wrapper& x) const throw () {
                return Wrapper (x_*x.x_);
        }
        Wrapper operator/ (const Wrapper& x) const throw () {
                return Wrapper (x_/x.x_);
        }
        Wrapper operator+ (const Wrapper& x) const throw () {
                return Wrapper (x_+x.x_);
        }
        Wrapper operator- (const Wrapper& x) const throw () {
                return Wrapper (x_-x.x_);
        }
        Wrapper operator- () const throw () {
                return Wrapper (-x_);
        }
        ~Wrapper () throw () {}
};

int main () {

        std::complex <Wrapper<double> > x (Wrapper<double>(2.0));
        std::pow (x, 23);

}

============================================================

OUTPUT:

debian:/# g++ bug.cpp --pedantic --std=c++98 -Wall
/usr/include/c++/3.3/bits/cmath.tcc: In function `_Tp std::__cmath_power(_Tp,
   unsigned int) [with _Tp = std::complex<Wrapper<double> >]':
/usr/include/c++/3.3/cmath:477:   instantiated from `_Tp std::__pow_helper(_Tp,
int) [with _Tp = std::complex<Wrapper<double> >]'
/usr/include/c++/3.3/complex:564:   instantiated from `std::complex<_Tp>
std::pow(const std::complex<_Tp>&, int) [with _Tp = Wrapper<double>]'
bug.cpp:29:   instantiated from here
/usr/include/c++/3.3/bits/cmath.tcc:42: error: no match for ternary
   'operator?:' in '((__n % 2) != 0) ? __x : 1'


-- 

bav dot 272304 at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bav dot 272304 at gmail dot
                   |                            |com
          Component|libstdc++                   |c++


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31511