undefined reference to function error in C++

Question

I have 3 files in c++

functions.h

void handle_1(std::string line);

functions.c

#include "functions.h"
void handle_1(string line)
{
//do something
}

main.c

#include <iostream>
#include "functions.h"
using namespace std;
int main()
{
    string line;
    getline(cin, line);
    handle_1(line);
}

I am getting the following error-
In function `main':

main1.cpp:(.text+0x116): undefined reference to 'handle_1(std::string)'

collect2: error: ld returned 1 exit status

score 3 · Answer 1 · answered Jul 25 '16 at 20:21

3

Use this:

g++ functions.c main.c -o main

answered Jul 25 '16 at 20:21

Ryan

functions.c does not compile. It need std::string in the parameter – EFenix Jul 25 '16 at 20:22
then do `#include ` at the top. – Ryan Jul 25 '16 at 20:22
3

But it will be better to rename `*.c` files to `*.cpp`, just because you want yo use C++ standard libraries – VolAnd Jul 25 '16 at 20:26

1 Answers1