regarding my Point struct already mentioned here:
template class: ctor against function -> new C++ standard is there a chance to replace the function toint() with a cast-operator (int)?namespace point {
template < unsigned int dims, typename T >
struct Point {
T X[ dims ];
//umm???
template < typename U >
Point< dims, U > operator U() const {
Point< dims, U > ret;
std::copy( X, X + dims, 开发者_开发技巧ret.X );
return ret;
}
//umm???
Point< dims, int > operator int() const {
Point<dims, int> ret;
std::copy( X, X + dims, ret.X );
return ret;
}
//OK
Point<dims, int> toint() {
Point<dims, int> ret;
std::copy( X, X + dims, ret.X );
return ret;
}
}; //struct Point
template < typename T >
Point< 2, T > Create( T X0, T X1 ) {
Point< 2, T > ret;
ret.X[ 0 ] = X0; ret.X[ 1 ] = X1;
return ret;
}
}; //namespace point
int main(void) {
using namespace point;
Point< 2, double > p2d = point::Create( 12.3, 34.5 );
Point< 2, int > p2i = (int)p2d; //äähhm???
std::cout << p2d.str() << std::endl;
char c; std::cin >> c;
return 0;
}
I think the problem is here that C++ cannot distinguish between different return types? many thanks in advance. regards
OopsThe correct syntax is
operator int() const {
...
There's no need to have that extra return type when you overload the cast operator.
And when you say (int)x
, the compiler really expects to get an int
, not a Point<dims, int>
. Probably you want a constructor instead.
template <typename U>
Point(const Point<dims, U>& other) { ... }
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