Re: [Boost-users] [function] using with CRTP

From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2008-01-23 13:41:22

AMDG

Russell L. Carter wrote:
> then I
> get "void value not ignored as it ought to be" at the line:
> "FooFunc ff = put.getFooFunc();"
>
> I get the same thing if I try: FooFunc ff = MHBase<Put>::fooFO(put);
>
> Here's the code:
>
> #include <boost/function.hpp>
> #include <iostream>
>
> class MHBAccessor {
>      template<class> friend class MHBase;
>      template<class Derived>
>      static int foo(Derived& derived, int i) { return derived.foo_(i); }
> };
> typedef boost::function<int (int)> FooFunc;
>
> template <class Derived>
> struct MHBase {
>      Derived& derived() { return static_cast<Derived&>(*this); }
>
>      int foo(int i) { return MHBAccessor::foo(this->derived(), i); }
>
>      struct fooFO {
>          fooFO(MHBase<Derived>& mhb) : mhb_(mhb) {}
>          void operator()(int i) { mhb_.foo(i); }
>   

This returns void.  FooFunc expects int.
try

int operator()(int i) { return(mhb_.foo(i)); }

In Christ,
Steven Watanabe