Re: Flex 2.5.23 beta and C++

[Hans Aberg]

At 11:21 -0400 2002/10/22, W. L. Estes wrote:
>> Have you tried
>>
>> using namespace std;
>>
>> which only needs to appear once near the top of the file,
>> (and only for C++) which is aimpler and less ugly than
>> either std:: everywhere or macro hacking.
>
>I'm just going to include standard C headers in c++ scanners for
>now. When the re-write happens, there will be a separate c++ skeleton
>and it'll be pure c++.

It is a bad idea to put in
   using namespace std;
as then all C++ std names will litter the global namespace. -- The problem
is that once introducing a "using" directive, there is no way to turn it
off. This is evidently a flaw with the C++ standard.

One alternative would be to write
  using std::malloc;
etc. This adds the only the name ::malloc, etc.

But I would favor to make the quick fix I suggested, which does not alter
the std namespace at all, and later work up a better separate C++ skeleton
file.

For example, I never understood the "virtual" stuff in the current C++
FlexLexer.h file: This "virtual" stuff is used when one actually want to
vary the object polymorphicly at runtime, which does not happen what I know
with the lexer itself.

If one wants to make a heap instantiation of a derived class, then one can
use that class name instead of the base class.

  Hans Aberg