模板函数不是名称空间的成员

Question

I have a header file, RandFunctions.hpp which contains a template function,

#ifndef _RANDFUNCTIONS_HPP_
#define _RANDFUNCTIONS_HPP_
#include <stdlib.h>
#include <time.h>

namespace surena
{
  namespace common
  {

template<typename RealT> inline
RealT
RealRandom()
{
  return rand()/(RealT(RAND_MAX)+1);
}  

  };
};
#endif

and another header file, Search.hpp which includes RandFunctions.hpp ,

#ifndef _SEARCH_HPP_
#define _SEARCH_HPP_

#include "RandFunctions.hpp"

#include <stdlib.h>
#include <time.h>

namespace surena
{
  namespace search
  {

template<typename RealT>
class CTest
{
  public:
    CTest() {srand((unsigned)(time(0)));}

    RealT
    GenRand(){ return common::RealRandom(); }
};

  };
};
#endif

when I include Search.hpp in a cpp file, for example,

#include "Search.hpp"

int
main(int argc, char** argv)
{
  CTest<float> test;
  return(0);
}

I get the following compile time error:

‘RealRandom’ is not a member of ‘surena::common’

What is wrong here?

Answer 1

Since RealRandom is a template function with no parameters, you need to provide a template argument:

GenRand(){ return common::RealRandom<RealT>(); }
                                    ^^^^^^^

Also in your main you'd have to qualify your test variable with the proper namespaces:

surena::search::CTest<float> test;
^^^^^^^^^^^^^^^^