Intel® C++ Compiler
Support and discussions for creating C++ code that runs on platforms based on Intel® processors.
7693 Discussions

Calling parent's method in constructor, with templates

jiri
New Contributor I
176 Views

Hi,

I've encountered something strange when calling a parent's method inside a constructor. If the class and the parent are templates, I get "error: identifier "go" is undefined" message. A minimal code example (tested with "icc (ICC) 14.0.1 20131008"):

template<typename T>
struct boom
{
	void go() {}
};

template<typename T>
struct boom2 : public boom<T>
{
	boom2()
	{
		go();
	}
};

boom2<int> aaa;

Without the templates, it works. It can also be fixed by replacing go() with this->go(), so it is not a big issue for me. But it makes me wonder, whether my code is correct. As far as I know, it should be, but I'm not really familiar with all the details of the C++ standard.

0 Kudos
1 Solution
Judith_W_Intel
Employee
176 Views

 

Your code is incorrect. Since you are using a dependent base class and you are using the name is an unqualified way the name will not be found.

See:

http://eli.thegreenplace.net/2012/02/06/dependent-name-lookup-for-c-templates/

http://womble.decadent.org.uk/c++/template-faq.html#base-lookup

Judy

View solution in original post

3 Replies
jiri
New Contributor I
176 Views

I've just noticed that the problem is not limited to calls from constructor, but from any method. Seems like I may doing something in a fundamentally wrong way.

Judith_W_Intel
Employee
177 Views

 

Your code is incorrect. Since you are using a dependent base class and you are using the name is an unqualified way the name will not be found.

See:

http://eli.thegreenplace.net/2012/02/06/dependent-name-lookup-for-c-templates/

http://womble.decadent.org.uk/c++/template-faq.html#base-lookup

Judy

jiri
New Contributor I
176 Views

Great! Thanks a lot for the explanation. So the code is indeed incorrect and the fix is correct. As I already wrote, I'm not really familiar with such details of C++, but the links explain it well.

Reply