在同一个名称空间中使用函数

Question

Have a query on function using function in the same namespace. How do I call the function? It seems to keep on giving me error.

Eg:

// in the .h files
namespace helper{ 
    void helper1();
    void helper2();
}

// in the cpp files
namespace helper{
    void helper1() { 
      // blah blah blah
    }

    void helper2() {
      // blah blah blah
      helper1();    // return some results from helper1
    }
}

The above code gives me error result, saying it can't find the helper1 function. Is there anything I have done wrongly?

Thanks for your help!

Answer 1

Are you sure you are asking the right quesiton? This is what I have, and it works fine:

// this is helper.cpp
#include<iostream>

#include "helper.hpp"

namespace helper{
void helper1() { 
  std::cout<<"calling helper 1"<<std::endl;
}

void helper2() {
  std::cout<<"calling helper 2"<<std::endl;
  helper1(); 
}
}

int main() {
  helper::helper2();
  return 0;
}

and the header file

//this is helper.hpp
namespace helper{ 
void helper1();
void helper2();
}

compiled using

g++ helper.cpp -ansi -Wall -Wextra -pedantic

returns no warnings and yields

$ ./a.out
calling helper 2
calling helper 1