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Re: Problem with calling C++ from Fortran

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db <dieterhansbritz@gmail.com> writes:

> On 09.09.2023 11.02, Muttley@dastardlyhq.com wrote:
>> On Sat, 9 Sep 2023 10:54:33 +0200
>> db <dieterhansbritz@gmail.com> wrote:
>>> but now it says that C-double doesn't exist.
>>>
>>> Any ideas?
>> C++ mangles function names so that the name you give the function isn't
>> the
>> name the dynamic loader sees in the binary. You need to put this around whatever
>> function you want to call from Fortran so it has C style linkage which means
>> the name remains the same:
>> extern "C" {
>> void calledFromFortran()
>> {
>> 	:
>> }
>> }
>> 
> Where should this go in the code? I added it at the end as is,
> and now I get this:
>
> ~/ownlib90/tests> ./jbandtest
> jband.cpp:88:1: error: expected initializer before 'extern'
>    88 | extern "C" {
>       | ^~~~~~
> jband.cpp:96:1: error: expected unqualified-id before '{' token
>    96 | {
>       | ^
> jband.cpp: In function 'void calledFromFortran()':
> jband.cpp:350:9: error: expected primary-expression before ':' token
>   350 |         :
>  ...

You are giving people very little to go on.  There's an unknown command
(./jbandtest) the gives some errors where only one line of code can be
seen.

Can you produce a cut-down version to the program that shows the same
error --  mimimal example of the C++ and of the Fortran that should
calls it but which fails?  That would mean you could post the code.

If that is not possible, can you link to the source so those who know
both C++ and Fortran can take a proper look?

-- 
Ben.

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Problem with calling C++ from Fortran db <dieterhansbritz@gmail.com> - 2023-09-09 10:54 +0200
  Re: Problem with calling C++ from Fortran Muttley@dastardlyhq.com - 2023-09-09 09:02 +0000
    Re: Problem with calling C++ from Fortran db <dieterhansbritz@gmail.com> - 2023-09-09 12:47 +0200
      Re: Problem with calling C++ from Fortran Muttley@dastardlyhq.com - 2023-09-09 10:51 +0000
      Re: Problem with calling C++ from Fortran db <dieterhansbritz@gmail.com> - 2023-09-09 12:52 +0200
        Re: Problem with calling C++ from Fortran Muttley@dastardlyhq.com - 2023-09-09 11:00 +0000
          Re: Problem with calling C++ from Fortran db <dieterhansbritz@gmail.com> - 2023-09-10 14:33 +0200
            Re: Problem with calling C++ from Fortran Paavo Helde <eesnimi@osa.pri.ee> - 2023-09-10 18:49 +0300
            Re: Problem with calling C++ from Fortran Muttley@dastardlyhq.com - 2023-09-11 08:23 +0000
        Re: Problem with calling C++ from Fortran Paavo Helde <eesnimi@osa.pri.ee> - 2023-09-09 16:56 +0300
          Re: Problem with calling C++ from Fortran db <dieterhansbritz@gmail.com> - 2023-09-10 14:36 +0200
          Re: Problem with calling C++ from Fortran James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-09-11 00:14 -0400
        Re: Problem with calling C++ from Fortran Bo Persson <bo@bo-persson.se> - 2023-09-10 16:08 +0200
      Re: Problem with calling C++ from Fortran "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2023-09-09 16:30 +0200
    Re: Problem with calling C++ from Fortran db <dieterhansbritz@gmail.com> - 2023-09-10 14:48 +0200
      Re: Problem with calling C++ from Fortran Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-10 14:22 +0100
        Re: Problem with calling C++ from Fortran Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-10 17:27 +0100
        Re: Problem with calling C++ from Fortran db <dieterhansbritz@gmail.com> - 2023-09-11 14:00 +0200
          Re: Problem with calling C++ from Fortran Michael S <already5chosen@yahoo.com> - 2023-09-11 05:21 -0700
          Re: Problem with calling C++ from Fortran Muttley@dastardlyhq.com - 2023-09-11 13:33 +0000
          Re: Problem with calling C++ from Fortran Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-12 00:26 +0100
            Re: Problem with calling C++ from Fortran db <dieterhansbritz@gmail.com> - 2023-09-12 10:48 +0200
              Re: Problem with calling C++ from Fortran Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-12 14:14 +0100
              Re: Problem with calling C++ from Fortran Michael S <already5chosen@yahoo.com> - 2023-09-12 07:15 -0700
            Re: Problem with calling C++ from Fortran Michael S <already5chosen@yahoo.com> - 2023-09-12 02:00 -0700
              Re: Problem with calling C++ from Fortran Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-09-12 14:22 +0100
                Re: Problem with calling C++ from Fortran Michael S <already5chosen@yahoo.com> - 2023-09-12 07:32 -0700
                Re: Problem with calling C++ from Fortran db <dieterhansbritz@gmail.com> - 2023-09-12 18:36 +0200
                Re: Problem with calling C++ from Fortran Michael S <already5chosen@yahoo.com> - 2023-09-19 02:39 -0700
  Re: Problem with calling C++ from Fortran Michael S <already5chosen@yahoo.com> - 2023-09-10 08:38 -0700
  Re: Problem with calling C++ from Fortran Michael S <already5chosen@yahoo.com> - 2023-09-10 09:51 -0700
    Re: Problem with calling C++ from Fortran Michael S <already5chosen@yahoo.com> - 2023-09-11 02:49 -0700
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