Re: a compiler error with template function

From:

Rolf Magnus <ramagnus@t-online.de>

Newsgroups:

comp.lang.c++

Date:

Sun, 06 May 2007 15:13:19 +0200

Message-ID:

<f1kk9g$6s4$02$1@news.t-online.com>

Jess wrote:

Hi,

I have a template function that triggered some compiler error. The
abridged version of the class and function is:

#include<memory>

using namespace std;

template <class T>
class Vec{
public:
  T* data;
  T* avail;
  T* limit;
  std::allocator<T> alloc;

  template<class In> void create (In,In);

};

template<class T,class In>
void Vec<T>::create(In i, In j){
  data = alloc.allocate(j - i);
  limit = avail = std::uninitialized_copy(i,j,data);
}

The compiler error was:
error: prototype for 'void Vec<T>::create(In, In)' does not match any
in class 'Vec<T>'
error: candidate is: template<class T> template<class In> void
Vec::create(In, In)
error: template definition of non-template 'void Vec<T>::create(In,
In)'

Well, that error message is quite self-explanatory, isn't it?

I guess I must have made some mistakes with the order of these type
parameters. Can someone please point out my mistakes?

You have a template template, so you have to define it like that:

template<class T>
template<class In>
void Vec<T>::create(In, In)