C++ member function pointers in ISO C++

[Nathan Sidwell]

Terry Barnaby wrote:
> 
> We are trying to compile some library code that passes the address of an
> objects member
> function together with the objects address to be used in a call-back
> method. Having upgraded
> to GCC 2.96 we now get a compilation error " ISO C++ forbids taking the
> address of a
> non-static member  function to form a pointer to member function.  Say
> `&A::Func1'"
> 
> Questions:
> 1. Is there a proper way in ISO C++ of passing and storing a pointer to
> a member function ?
yes see 5.3.1/3 a pointer to member is only formed with an explicit
& is used and its operand is a qualified-id not enclosed in parentheses.
See also 13.4. gcc 2.95.2 could give this warning too early, when static
and non-static member fns have the same name, and overload resolution gets
the static member fn.
you have to write &Class::member, not Class::member (no decay to ptr),
not &(Class::member), not &member in a member of Class.

> 2. Is there a compiler switch or other mechanism to allow the previous
> GCC behaviour ?
-fms-extensions IIR

nathan

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