Re: [Boost-users] Delegating to boost::function with arbitrary signature

16 Dec 2013

      2013/12/16 Alexander Lamaison 
...
TONGARI J  writes:
...
template<typename Signature>
 class library_function
 {
 public:
     library_function(
         shared_ptr<HMODULE> library, Signature* library_funtion)
         :
     m_library(library),
     m_function(library_function)
     {}
operator Signature*() const { return m_function; }
private:
     shared_ptr<HMODULE> m_library;     Signature* m_function;
 };Note: code not tested
This works well.  The key was `operator Signature*()`.  Clever idea,
thanks!
I didn't expect it to work because I though `boost::function` would pull
out the `Signature*` via the cooersion operator, and then the
`library_function` would be destroyed before the call was made.
However, this code proves that it has the desired behaviour, so it must
be keeping a copy of the `library_function` instance inside
`boost::function`: http://ideone.com/BZvuk9.
I didn't use`make_library_function` because inferring the signature
from the raw function isn't something I need.
If you would like to add this answer to the Stack Overflow qusetion,
I'll happily give you the brownie points :)
Done: http://stackoverflow.com/a/20614403/2969631

BTW, the reason why I knew this trick is because I implemented this:

    http://tinyurl.com/mptekbr

and it credits to Proto.