Re: [Boost-users] Comparing boost::function<void()>

On May 4, 2007, at 7:51 PM, Rennie deGraaf wrote:

Could anyone please tell me why the following code fails to compile:

...

inline void rmfunc(std::list >& funcs, boost::function f) { for (std::list >::iterator i=funcs.begin(); i!=funcs.end(); ++i) { if (boost::function_equal(*i, *f)) i = funcs.erase(i); } }

while the following does compile:

...

template <typename T> inline void rmfunc(std::list >& funcs, const T& f) { for (std::list >::iterator i=funcs.begin(); i!=funcs.end(); ++i) { if (boost::function_equal(*i, f)) i = funcs.erase(i); } }

and seemingly equivalent code, placed in-line in the calling function, also compiles?

You cannot compare two boost::function objects directly, because it can't be implemented. See the first question on http://www.boost.org/ doc/html/function/faq.html - Doug