how to call C++ from C?

I have some C++ code that I would like to call from within a C program
C does not define any way to do this, making this off-topic in
comp.lang.c. C++ sort of defines a way to do it, so comp.lang.c++ is
appropriate. Cross-posted and followups set.

[Remainder of message left intact for clc++.]
(main() is within the C code). How do I go about doing this portably?
I know that I can find the mangled name of the C++ functions, but
this is kind of weird.

I am using gcc and g++ on Linux, if that matters.
Here is an example of what I'm doing:
---------------------------------------------------
a.c:
---------------------------------------------------
#include "b.h"
int main()
{
foo();
}
---------------------------------------------------
b.h
---------------------------------------------------
int foo();

---------------------------------------------------
b.cpp
---------------------------------------------------
#include <map>
int foo()
{
map<int, int> m;

}
---------------------------------------------------
Makefile
---------------------------------------------------
a.out: a.o b.o
g++ a.o b.o

a.o: a.c
gcc -c a.c

b.o: b.cpp
g++ -c b.cpp

I have some C++ code that I would like to call from within a C
program (main() is within the C code). How do I go about doing this
portably?
I know that I can find the mangled name of the C++ functions, but
this is kind of weird.

and sizeof(int) in C. Also you have to be careful if you are using stdin /
stdout and cin / cout in the same program.

[It] should be no problem.

Martijn Lievaart writes:

[It] should be no problem.

osmium <r1********@comcast.net> wrote in message
news:bt************@ID-179017.news.uni-berlin.de...

Martijn Lievaart writes:

> [It] should be no problem.

Famous last words! I have had problems due to this.

Sorry for the blank post.

I have some C++ code that I would like to call from within a C program
(main() is within the C code). How do I go about doing this portably?
I know that I can find the mangled name of the C++ functions, but
this is kind of weird.

I am using gcc and g++ on Linux, if that matters.

"Digital Puer" <di**********@hotjail.comet> wrote in message

I have some C++ code that I would like to call from within a C
program (main() is within the C code). How do I go about doing this
portably?
I know that I can find the mangled name of the C++ functions, but
this is kind of weird.

Convert your C code to C++ code. Generally this is quite easy, all you need
to do is change the file extension and a few implicit casts of void *s (this

There's no such thing as an "implicit cast". Casts are explicit by
definition.
is an illustration why the advice not to cast the return from malloc() isn't
necessarily very good).
The advice not to cast malloc is fine (for most purposes). Your advice
to convert a source file from one language to another, on the other
hand, is questionable. It amounts to wasted effort creating bad C++ code
from (possibly) good C code, and quite possibly introducing bugs, when
the OP should obviously just use the technique C++ provides for
interfacing the two languages.
There are a few niggly incompabilities between C and C++ which could just
wreck things, such as the fact that sizeof('c') yields sizeof(char) in C++
and sizeof(int) in C. Also you have to be careful if you are using stdin /
stdout and cin / cout in the same program.

No you don't, they're tied together. I should be no problem.