I'm trying to define a custom sequence for use by the replace_all()
function of boost::string::algo. I'm hitting an error that I am not able
to decipher the cause of.
In the Finder concept check in find_format.hpp (Line 238), I'm getting
two errors:
Error : illegal template argument(s)
(point of instantiation: 'SpecifyItem(const unsigned char *, const
unsigned char *, bool)')
(instantiating: 'boost::algorithm::replace_all(sequence &, const unsigned char
*const &, const unsigned char *const &)')
(instantiating: 'boost::algorithm::find_format_all, boost::a
lgorithm::detail::const_formatF>(sequence &,
boost::algorithm::detail::first_finderF, boost::a
lgorithm::detail::const_formatF)')
find_format.hpp line 238 BOOST_STRING_TYPENAME
const_iterator_of<SequenceT>::type> >();
Error : '(' expected
(point of instantiation: 'SpecifyItem(const unsigned char *, const
unsigned char *, bool)')
(instantiating: 'boost::algorithm::replace_all(sequence &, const unsigned char
*const &, const unsigned char *const &)')
(instantiating: 'boost::algorithm::find_format_all, boost::a
lgorithm::detail::const_formatF>(sequence &,
boost::algorithm::detail::first_finderF, boost::a
lgorithm::detail::const_formatF)')
find_format.hpp line 238 BOOST_STRING_TYPENAME
const_iterator_of<SequenceT>::type> >();
The sequence I am defining wraps a Macintosh style Pascal string. (For
those not in the know, these are a string where the first byte is the
length. The character type is also unsigned char.)
I am defining the sequence called sequence:
class sequence
{
public:
sequence() {}
sequence( unsigned char* in_sequence )
: sequence( in_sequence ) {}
typedef unsigned char value_type;
typedef std::ptrdiff_t difference_type;
typedef std::size_t size_type;
typedef unsigned char* iterator;
typedef const unsigned char* const_iterator;
iterator begin() { return &sequence[1]; }
const_iterator begin() const { return &sequence[1]; }
iterator end() { return &sequence[ sequence[0] ]; }
const_iterator end() const { return &sequence[ sequence[0] ]; }
private:
unsigned char* sequence;
};
This isn't complete, but I thought I could get a little farther than
this or at least understand what I am missing from the definition that
this concept check doesn't fail.
I am using it like this:
void SpecifyItem( unsigned string* in_pascal_string )
{
sequence seq( in_pascal_string );
const unsigned char* find_this = "\pa";
const unsigned char* replace_with = "\pb";
boost::algorithm::replace_all( seq, find_this, replace_with );
}
I also don't have a copy of the spec to understand all of the
requirements for a sequence, so I was shooting in the dark emulating a
vector to see how for I could get. I expected to get a little farther. :-)
Thanks for any tips,
...Duane
