multi_pass_iterator not flushed automatically by expectation operator

[Jeff Flinn <jflinn@…>]

Parsing a 2GB file, multi_pass_iterator throws std::bad_alloc when it tries to push_back the ~1.2GB'th item, even though expectation operator is used with a record based file whose max record length is ~200 chars. For example:

start %= header > *rec;

I also tried:

start %= header > flush_multi_pass *rec;

which resulted in no effect.

note: 1.47.0 required modifying flush_multi_pass.hpp to be the same as 1.48.0 impl to avoid compilation errors

[Antony Polukhin]

boost::spirit::lex::lexertl::iterator<Functor> class has no functions specializations in traits namespace, which makes it to choose the default methods that do nothing (instead of calling clear_queue).

Attached patch for boost/spirit/home/lex/lexer/lexertl/iterator.hpp that fixes it.

P.S.: boost::spirit::lex::lexertl::iterator<Functor> also has no swap specialisation, which may lead to use of ineffective std::swap.

[Hartmut Kaiser]

(In [83461]) Fix #6248: multi_pass_iterator not flushed automatically by expectation operator