hash_map error: passing `const lambda_calculus::int_adr' as `this' argument of `const size_t lambda_calculus::int_adr::operator ()(const lambda_calculus::Port *)' discards qualifiers passing `const lambda_calculus::int_adr' as `this' argument of `const size_t lambda_calculus::int_adr::operator ()(const lambda_calculus::Port *)' discards qualifiers

Have you ever seen this error?,

 it means that I pass a pointer to a constant object out of it's protected 
context. Yes I cast it down to a normal pointer indeed. The pointer is actually 
casted to an integer. I'm keeping a hash of memory adresses with 
the adresses of kopies of the objects these adresses refer too. So I do not 
alter this const pointer. Here is the code:

//hash function object for the Mem_hash
class int_adr
{public:
const size_t operator()(const Port* const a)
    {  int i;
     /*haha, fooled ya*/   here is the fooling part that actually works on 
other compilers
      const Port * const s= a;//(Port *)a;
      i=(int)s;
     return i;
    }
};

//hash of memory adresses
typedef std::hash_map< const Port *, Port *, int_adr , equal_to <const Port * > 
> Mem_hash;

all these const identifiers are required by hash_map, the non-standard gnu 
stl-extension.

I don't wnat to change code that works with other compilers I need some 
compiler option or something to disable the error.

error mess:

gcc  -g -c -I/sw/pkg/gcc-2.95.2/include/g++-3  -I./loki main.cpp
stl_hashtable.h: In method `size_t hashtable<pair<const lambda_calculus::Port 
*const,lambda_calculus::Port *>,const lambda_calculus::Port 
*,lambda_calculus::int_adr,_Select1st<pair<const lambda_calculus::Port 
*const,lambda_calculus::Port *> >,equal_to<const lambda_calculus::Port 
*>,allocator<lambda_calculus::Port *> >::_M_bkt_num_key(const 
lambda_calculus::Port *const &, unsigned int) const':

stl_hashtable.h:536:   instantiated from `hashtable<pair<const 
lambda_calculus::Port *const,lambda_calculus::Port *>,const 
lambda_calculus::Port *,lambda_calculus::int_adr,_Select1st<pair<const 
lambda_calculus::Port *const,lambda_calculus::Port *> >,equal_to<const 
lambda_calculus::Port *>,allocator<lambda_calculus::Port *> >::_M_bkt_num(const 
pair<const lambda_calculus::Port 
*const,lambda_calculus::Port *> &, unsigned int) const'

stl_hashtable.h:930:   instantiated from `hashtable<pair<const 
lambda_calculus::Port *const,lambda_calculus::Port *>,const 
lambda_calculus::Port *,lambda_calculus::int_adr,_Select1st<pair<const 
lambda_calculus::Port *const,lambda_calculus::Port *> >,equal_to<const 
lambda_calculus::Port *>,allocator<lambda_calculus::Port *> >::resize(unsigned 
int)'

stl_hashtable.h:744:   instantiated from `hashtable<pair<const 
lambda_calculus::Port *const,lambda_calculus::Port *>,const 
lambda_calculus::Port *,lambda_calculus::int_adr,_Select1st<pair<const 
lambda_calculus::Port *const,lambda_calculus::Port *> >,equal_to<const 
lambda_calculus::Port *>,allocator<lambda_calculus::Port *> 
>::find_or_insert(const pair<const lambda_calculus::Port 
*const,lambda_calculus::Port *> &)'

stl_hash_map.h:181:   instantiated from here

stl_hashtable.h:531: passing `const lambda_calculus::int_adr' as `this' 
argument of `const size_t lambda_calculus::int_adr::operator ()(const 
lambda_calculus::Port *)' discards qualifiers
make: *** [main.o] Error 1

if you do got an idea please respond to buggy@xxxxxxxxx or to the list

thanks

ali