Re: [boost] compiling function library with an old compiler

From: Douglas Gregor (gregod_at_[hidden])
Date: 2001-10-06 15:36:03

On Saturday 06 October 2001 02:27, you wrote:
> Hi guys,
>  I am using boost 1.25.0 on a platform (linux/ egcs 1.1.2) that does not
> provide std::allocator. The function library seems to be protected
> against this defect as it makes liberal use of the macro
> BOOST_NO_STD_ALLOCATOR. Unfortunately, even if I define the macro, I get
> a compilation error in function_template.hpp at line 420 (there is a
> similar construct at function.hpp:58)
>   template<
>     typename R BOOST_FUNCTION_COMMA
>     BOOST_FUNCTION_TEMPLATE_PARMS,
>     typename Policy    = empty_function_policy,
>     typename Mixin     = empty_function_mixin,
>     typename Allocator = std::allocator<function_base>   <<<<<<<<<here
>
>   class BOOST_FUNCTION_FUNCTION : public function_base, public Mixin
>
> the error is obvious, but I haven't been able to ifdef my way out of it.
>
> Can the authors/experts suggest a workaround or should I just give up
> using the function library?

I don't currently have access to egcs-1.1.2, but it is possible that the 
function library will work if "std::allocator<function_base>" to "void" (when 
BOOST_NO_STD_ALLOCATOR is defined). I just checked an updated version into 
CVS, but essentially I just added:

#ifndef BOOST_NO_STD_ALLOCATOR
#  define BOOST_FUNCTION_DEFAULT_ALLOCATOR std::allocator<function_base>
#else
#  define BOOST_FUNCTION_DEFAULT_ALLOCATOR void
#endif // BOOST_NO_STD_ALLOCATOR

to function_template.hpp, along with an 
#undef BOOST_FUNCTION_DEFAULT_ALLOCATOR

at the end. Then replaced "std::allocator<function_base>" with 
"BOOST_FUNCTION_DEFAULT_ALLOCATOR"

I'd be interested to know if this fixes function on egcs-1.1.2.

        Doug