Writing a vector to a file

[StrathScot]

I have written a function that is supposed to write a vector to a specified file.
When I build the solution, I get this error:

- Semantic error. Invalid operands to binary expression.

This is the code for the function.

void file_out(vector<task>Task, string myfilename){
    //writing vector to file

    string file_out = myfilename;
    ofstream output_file(file_out);
    ostream_iterator<task> output_iterator(output_file, "\n");
    copy(Task.begin(), Task.end(), output_iterator);
};

Thank you for any help given.

[xkcd83]

what is the copy function?
Write a for/while loop with iterator, and ostream operator
for(it=Task.begin();it<Task.end();it++)
output_file<< (data you want to write)...

[cire]

I suspect you only supplied part of the error message.

Do you have operator<< overloaded correctly?

@xkcd83: http://www.cplusplus.com/reference/algorithm/copy/

[StrathScot]

Full error reads:

invalid operand to binary expression ('ostream_type'(aka'basic_ostream<char,std::_1::char_traits<char> >') and 'const task')

and its to do with the iterator ... still don't understand what the error is.

[cire]

That still doesn't look like the full error message. What binary expression? And it doesn't look like it has anything to do with the iterator, as the types are std::ostream and const task (which again, suggests operator<< to me.)

[xkcd83]

shouldn't it matter which data member/s of the task class are you trying to copy?

[StrathScot]

Thanks, it was an error to do with const task
Sorted!

[cire]

Perhaps a working example will be more productive.

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#include <iostream> #include <iterator> #include <vector> #include <algorithm> class task { }; std::ostream& operator<<(std::ostream& os, const task&) { return os << "task" ; } void output(std::ostream& os, const std::vector<task>& t) { std::ostream_iterator<task> output_iterator(os, "\n") ; std::copy(t.begin(), t.end(), output_iterator) ; } int main() { std::vector<task> taskVec(5) ; output(std::cout, taskVec) ; }

task task task task task