Thread: returning a vector in a function, how to?

Originally Posted by Salem

> std::vector <std::string> * fill_vector(char *file)
You need to remove the *
You're not returning a pointer, you're returning an actual vector.

Assuming your header file includes <vector> and <string>.

Then make the parameter
const char *file

Ok

here is where I am at.

Code:

 

void  fill_vector(char *file)
{
    std::vector <std::string> FileList;
    std::string sfile(file);
    FileList.push_back(sfile);
 
    int s = FileList.size();
    for( int i = 0; i < s ; i++) {
        std::cout << FileList[i]<< " vector"<< '\n';
    }
 

  //  return FileList; 
}

that works, I get output of every file in the directories .

when I change the to return

Code:

std::vector <std::string>   fill_vector(char *file)
{
    std::vector <std::string> FileList;
    std::string sfile(file);
    FileList.push_back(sfile);
 
/*
    int s = FileList.size();
    for( int i = 0; i < s ; i++) {
        std::cout << FileList[i]<< " vector"<< '\n';
    }
 */

    return FileList; 
}

header is the same as the declaration

Code:

std::vector <std::string>   fill_vector(char *file);

still getting error, I too added the include vector header file, as stated It is getting filled . and prints out by the use of that loop within the function.

still gettting this

Code:

[Running] cd "/media/data/projects/VSC/C++/mh5000/" && g++ -Wall -std=gnu++1z *.cpp
In file included from main.cpp:3:0:
files.h:21:6: error: 'vector' in namespace 'std' does not name a template type
 std::vector <std::string>   fill_vector(char *file);
      ^~~~~~
In file included from options.cpp:4:0:
files.h:21:6: error: 'vector' in namespace 'std' does not name a template type
 std::vector <std::string>   fill_vector(char *file);

both main.cpp, and options.cpp have the #include "files.h "

so I got to stick #include <vector> in every cpp that is not even using it within the cpp of that file if one file (cpp) is using it?

because that is what I did and the errors are no longer there.

the pointer what a shot in the dark . but yeah. ok

so I got to stick #include <vector> in every cpp that is not even using it within the cpp of that file if one file (cpp) is using it?

No, you either get vector through the included header, or you include it explicitly. But you never need to include vector in a cpp file that doesn't use it.

It seems to me like you're over-complicating things. You can push_back a char* directly into a vector<string>, no need for a function. Or are you writing these to explore your understanding of C++?

p.s. As someone else pointed out, you should use -std=c++1z, not gnu++. It does not matter in this case, but you should stick to the other in general.

Also -Wextra -pedantic are good options, especially when learning. Seriously, make use of them!

Originally Posted by Guest

No, you either get vector through the included header, or you include it explicitly. But you never need to include vector in a cpp file that doesn't use it.

It seems to me like you're over-complicating things. You can push_back a char* directly into a vector<string>, no need for a function. Or are you writing these to explore your understanding of C++?

p.s. As someone else pointed out, you should use -std=c++1z, not gnu++. It does not matter in this case, but you should stick to the other in general.

that is what I thought, got a add it the the file it is being used in. but this thing complained, then I added it to the other files. and it stopped.

what if it is using a function call within that file that the function call is using the vector?

:
note
:
try
-std=c++1z