7

Simple Types

Simple types pass in a straightforward way, as in the following example:

The Pascal function,

function

RetReal (r: real): real;

RetReal.p

 

 

 

 

 

 

begin

 

 

 

 

RetReal := r + 1

 

end;

 

 

 

 

The C++ main program,

 

 

 

 

#include

<stdio.h>

RetRealMain.cc

 

 

 

 

 

 

extern "C" double RetReal (double);

 

int

main(void)

 

{

 

 

 

 

 

double

r,

s;

 

r

=

2.0;

 

 

s

=

RetReal

(r);

 

printf (" %f \n", s);

 

}

 

 

 

 

 

 

 

 

 

 

The commands to compile and execute RetReal.p and

RetRealMain.cc

hostname% pc -c RetReal.p

hostname% CC RetReal.o RetRealMain.cc -lpchostname% a.out

3.000000

The C++–Pascal Interface

153