problem with inner class of a class template as member function returntype

[Fei Liu]

Hello, I am having trouble to properly construct the 'show' function
definition. g++ 4.1.1 is giving me error messages but intel c++ compiler
compiles it fine. Which one is correct?

Fei

#include <iostream>
using namespace std;

template <typename T>
struct C{
struct S{
T x;
};

S s;
S show();
};

template <typename T>
C<T>::S C<T>::show(){
cout << s.x << '\n';
return s;
}

int main(){

C<int> c;
c.show();
}
~


~


~

 

[Victor Bazarov]

Hello, I am having trouble to properly construct the 'show' function
definition. g++ 4.1.1 is giving me error messages but intel c++
compiler compiles it fine. Which one is correct?

Fei

#include <iostream>
using namespace std;

template <typename T>
struct C{
struct S{
T x;
};

S s;
S show();
};

template <typename T>
C<T>::S C<T>::show(){
cout << s.x << '\n';
return s;
}

int main(){

C<int> c;
c.show();
}
~

Seems fine to me. What error do you get from gcc?

BTW, Comeau online accepts it as well.

V

 

[Fei Liu]

Seems fine to me. What error do you get from gcc?

BTW, Comeau online accepts it as well.

V

g++ -fstrict-aliasing -fomit-frame-pointer -Wall -pedantic -ansi -g -O0
-o templ_inner_class.o -c templ_inner_class.cpp
templ_inner_class.cpp:15: error: expected constructor, destructor, or
type conversion before ‘C’
gcc version 4.1.2 20061115 (prerelease)

 

[Victor Bazarov]

g++ -fstrict-aliasing -fomit-frame-pointer -Wall -pedantic -ansi -g
-O0 -o templ_inner_class.o -c templ_inner_class.cpp
templ_inner_class.cpp:15: error: expected constructor, destructor, or
type conversion before 'C'
gcc version 4.1.2 20061115 (prerelease)

Perhaps a 'typename' would silence it:

template <typename T>
typename // this here
C<T>::S C<T>::show(){ ...

V

 

[Fei Liu]

Perhaps a 'typename' would silence it:

template <typename T>
typename // this here
C<T>::S C<T>::show(){ ...

V

Yeap, this is the fix for g++, thanks!

Fei