How to call a function by a string of name & How to get the name of aclass?

[cutecutemouse]

---------------------------This is my
task:--------------------------------------
There are hundred of similar classes and a large file(in processing)
with thousand of instances of these classes. I should export these
instances into a XML file (I use Tiny XML), however not total
instances, but these which belong to the selected classes and the
selected attributes(member variable and value). In advance, I will
have a configuration file (also XML format), to define which classes
and which attributes we need, that is a user-defined file.
The problem are:

1, How do I get the name of a class? Just like by Java the
method .getclass() or instanceof ?

2, Is it possible to have such as an iterator to traverse through
all the variables/functions, to only call the functions and to get
the values of variables we need by name?

Thank you very much for your reply, indeed.

[Sam]

cutecutemouse writes:

1, How do I get the name of a class? Just like by Java the
method .getclass() or instanceof ?

2, Is it possible to have such as an iterator to traverse through
all the variables/functions, to only call the functions and to get
the values of variables we need by name?

Thank you very much for your reply, indeed.

No, there is no equivalent of Java-like reflection classes in the standard
C++ language. The only thing that's available in the standard C++ language
is a facility for retrieve an "implementation-defined" name of the object's
class, which may not necessary be the human-readable class name.

Having said that, your C++ compiler may or may not have its own
compiler-specific facilities for run-time type information that provides
more information than the C++ language standard requires. Check your
compiler's documentation for more information.

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)

iEYEABECAAYFAkhtXh4ACgkQx9p3GYHlUOI+sgCffGkGm9Mttj gyy+UM4LlXSjGv
C4IAn0dz+SoTOg5pBHxMRwojL5HoB140
=flFV
-----END PGP SIGNATURE-----

[Pascal J. Bourguignon]

cutecutemouse <pl******@hotmail.comwrites:

---------------------------This is my
task:--------------------------------------
There are hundred of similar classes and a large file(in processing)
with thousand of instances of these classes. I should export these
instances into a XML file (I use Tiny XML), however not total
instances, but these which belong to the selected classes and the
selected attributes(member variable and value). In advance, I will
have a configuration file (also XML format), to define which classes
and which attributes we need, that is a user-defined file.
The problem are:

1, How do I get the name of a class? Just like by Java the
method .getclass() or instanceof ?

Using RTTI:

template <class Classstd::string getClass(Class* object){
return unmangle(typeid(*object).name());
}

You will have to implement the unmangle function for your compiler...

2, Is it possible to have such as an iterator to traverse through
all the variables/functions, to only call the functions and to get
the values of variables we need by name?

You'll get no help from C++, but it's possible.

Here are two ways:

- use the source (parse it, or use the UML model if you design your
program from an UML CASE tool), and generate from it the meta
objects needed to do it.

- compile your program with a lot of debugging information (-ggdb3
-gdwarf-2 etc), and then use these debugging information to do
introspection at run-time, like any debugger would do it.

Here is also a third way to solve your problem, since you know before
hand what class and what member you need to access (from your xml
configuration files), you can use them to generate the C++ code that
will do the job.

--
__Pascal Bourguignon__

[cutecutemouse]

I've found a third-party Reflection API "Reflex" for it. Thank you!

On 4 Jul., 01:17, Sam <[e-mail]:

cutecutemouse writes:

1, How do I get the name of a class? Just like by Java the
method .getclass() or instanceof ?

2, Is it possible to have such as an iterator to traverse through
all the variables/functions, to only call the functions and to get
the values of variables we need by name?

Thank you very much for your reply, indeed.

No, there is no equivalent of Java-like reflection classes in the standard
C++ language. The only thing that's available in the standard C++ language
is a facility for retrieve an "implementation-defined" name of the object's
class, which may not necessary be the human-readable class name.

Having said that, your C++ compiler may or may not have its own
compiler-specific facilities for run-time type information that provides
more information than the C++ language standard requires. Check your
compiler's documentation for more information.

application_pgp-signature_part
1KHerunterladen