SOLVED: difference C vs C++ for importing simple function

[abakoboParticipant]

I’ve trouble with the difference with c and c++

I’ve copied some C example code from the net to be sure i’m using real C style. http://gribblelab.org/CBootcamp/12_Compiling_linking_Makefile_header_files.html (at the half page)
It works if I put the content of the .c file in a .cpp file.

What’s wrong there? I know chipmunk is in C but it’s first .h .c files are so complex that I can’t find what makes it ok to be in the .c format!
(a zip file with all files is attached)

I get the following error when importing the .c file:

Monkey

[crayon-5cba8d82855d1543873469 inline="true" ] _1src_2prime_0prime.cpp.o:prime_prime.cpp:(.text+0x101): undefined reference to isPrime(int)

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[crayon-5cba8d82855d1543873469 inline="true" ] _1src_2prime_0prime.cpp.o:prime_prime.cpp:(.text+0x101): undefined reference to isPrime(int)

[/crayon]

The files
prime.monkey2:

Monkey

[crayon-5cba8d82855d9431943551 inline="true" ] #Import "<std>" #Import "primes.h" 'switch above commented lines to get it working or not.. '#Import "primes.cpp" #Import "primes.c" Using std.. Extern Function isPrime:int(n:Int) Public Function Main() Print "Hello World" Print isPrime(7) End

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[crayon-5cba8d82855d9431943551 inline="true" ]   #Import "<std>" #Import "primes.h"   'switch above commented lines to get it working or not..   '#Import "primes.cpp" #Import "primes.c"   Using std..   Extern Function isPrime:int(n:Int)   Public Function Main()   Print "Hello World" Print isPrime(7) End

[/crayon]

primes.h

Monkey

[crayon-5cba8d82855e1195436504 inline="true" ] int isPrime(int n); // returns 0 if n is not prime, 1 if n is prime

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[crayon-5cba8d82855e1195436504 inline="true" ] int isPrime(int n); // returns 0 if n is not prime, 1 if n is prime

[/crayon]

primes.c or primes.cpp

Monkey

[crayon-5cba8d82855e6372177019 inline="true" ]int isPrime(int n) { // returns 0 if not prime, 1 if prime if (n<2) return 0; // first prime number is 2 if (n==2) return 1; // ensure 2 is identified as a prime if ((n % 2)==0) return 0; // all even numbers above 2 are not prime int i; for (i=3; i*i < n; i++) { // test divisibility up to sqrt(n) if ((n % i) == 0) { return 0; } } return 1; }

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[crayon-5cba8d82855e6372177019 inline="true" ]int isPrime(int n) {     // returns 0 if not prime, 1 if prime      if (n<2) return 0;         // first prime number is 2   if (n==2) return 1;        // ensure 2 is identified as a prime   if ((n % 2)==0) return 0;  // all even numbers above 2 are not prime      int i;   for (i=3; i*i < n; i++) {  // test divisibility up to sqrt(n)     if ((n % i) == 0) {       return 0;     }   }   return 1; }

[/crayon]

I’ve tried with #include “prime.h” in the .c file but same problem..

Attachments:

1. prime.zip

[abakoboParticipant]

Solved:
Adding this at the beginning of files

Monkey

[crayon-5cba8d828c569999873376 inline="true" ]#ifdef __cplusplus extern "C" { #endif

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[crayon-5cba8d828c569999873376 inline="true" ]#ifdef __cplusplus extern "C" { #endif

[/crayon]

and this at the end

Monkey

[crayon-5cba8d828c56f944244140 inline="true" ]#ifdef __cplusplus } #endif

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[crayon-5cba8d828c56f944244140 inline="true" ]#ifdef __cplusplus } #endif

[/crayon]

And I can now switch the .c and .cpp files.
Looks like mx2 is cpp by default..

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