2012/11/7 Pierre Talbot <ptalbot@mopong.net>

Hello,

I have a compilation error with Boost (1.52) and g++ (4.7) with the flag -Weffc++:

error: base class ‘class boost::static_visitor<std::**basic_string<char>

...

’ has a non-virtual destructor [-Werror=effc++]

And the static_visitor class is defined with a protected non-virtual destructor:

template <typename R = ::boost::detail::static_**visitor_default_return> class static_visitor : public detail::is_static_visitor_tag { public: // typedefs

typedef R result_type;

protected: // for use as base class only

static_visitor() { } ~static_visitor() { }

};

Is it normal ? And if it is, how to avoid this error ?

Thank you for your help,

Pierre Talbot.

I think your compiler is wrong about this. Please see "Guideline #4: A base class destructor should be either public and virtual, or protected and nonvirtual." [1] ;-) HTH, Kris [1] http://www.gotw.ca/publications/mill18.htm

AMDG On 11/07/2012 10:30 AM, Pierre Talbot wrote:

Hello,

I have a compilation error with Boost (1.52) and g++ (4.7) with the flag -Weffc++:

I would strongly advise against using this flag with Boost. For large parts of Boost, the rules that -Weffc++ checks are simply not applicable, and trying to comply with them would be a huge burden for no gain.

error: base class ‘class boost::static_visitor<std::basic_string<char>

...

’ has a non-virtual destructor [-Werror=effc++]

And the static_visitor class is defined with a protected non-virtual destructor:

template <typename R = ::boost::detail::static_visitor_default_return> class static_visitor : public detail::is_static_visitor_tag { public: // typedefs

typedef R result_type;

protected: // for use as base class only

static_visitor() { } ~static_visitor() { }

};

Is it normal ? And if it is, how to avoid this error ?

In Christ, Steven Watanabe