Using Vector Iterator

devilishruby · #1 13-Feb-2009, 13:02

What is my mistake? When I compile this code I encountered error as displayed below

CPP / C++ / C Code:

namespace VL{
class Sift
{
struct Keypoint
  {
    int o ;    ///< Keypoint octave index

    int ix ;   ///< Keypoint integer X coordinate (unnormalized)
    int iy ;   ///< Keypoint integer Y coordinate (unnormalized)
    int is ;   ///< Keypoint integer scale indiex

    float_t x  ;  ///< Keypoint fractional X coordinate
    float_t y  ;  ///< Keypoint fractional Y coordinate
    float_t s ;   ///< Keypoint fractional scale index

    float_t sigma ;  ///< Keypoint scale
  } ; 

  typedef std::vector<Keypoint>     Keypoints ;          ///< Keypoint list datatype
  typedef Keypoints::iterator       KeypointsIter ;      ///< Keypoint list iter datatype
  typedef Keypoints::const_iterator KeypointsConstIter ; ///< Keypoint list const iter datatype
  .
  .
  }
  .
  .
  .
  }//namespace VL

CPP / C++ / C Code:

 

 myFunction()
  {
  VL::Sift::KeypointsIter VectKeypointsIter;
  
  Keypoints keypoints ;
  
  VectKeypointsIter=keypoints.begin();
  }

Code:


error C2440: '=' : cannot convert from 'struct std::pair<struct VL::Sift::Keypoint,float> *' to 'struct VL::Sift::Keypoint *'
        Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast

davekw7x · #2 14-Feb-2009, 08:38

Quote:

Originally Posted by devilishruby

What is my mistake?

CPP / C++ / C Code:

namespace VL{
class Sift
{
  struct Keypoint
  {
  .
  .
  .
  typedef std::vector<Keypoint>     Keypoints ;          ///< Keypoint list datatype
  typedef Keypoints::iterator       KeypointsIter ;      ///< Keypoint list iter datatype
  .
  .
  .
}//namespace VL
.
.
.
 myFunction()
{
    VL::Sift::KeypointsIter VectKeypointsIter; 
    Keypoints keypoints ;
 
. 
}

...

You published enough for me to guess:

KeypointsIter is defined with a typedef in the Sift class in the VL namespace.
Since you didn't post an error message concerning VectKeypointsIter, I am assuming that the compiler recognized the typedef. (That is, I think that you are using it properly when declaring VectKeypointsIter.)
Keypoints is defined with a typedef in the Sift class in the VL namespace. It appears to have the same properties as the other typedef, therefore wouldn't you use it in a like manner when declaring keypoints?

Why would you use one typedef one way and the other differently?

Regards,

Dave

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Rate This Thread
Rate This Thread:

Using Vector Iterator

Re: Using Vector Iterator