100 days of code

Please post all the new concepts and problems you have faced in this forum which will save time of the others.

Hey there thanks for inviting

#include <iostream>
#include <vector>
#include <sstream>
using namespace std;

template <class T>
T addall(vector <T>list){
T count=0;
for(auto &c:list)
count+=c;

return count;
}

template <>
string addall(std::vector<string>list){
int count=0;
for(auto &c:list){
for(auto &l:c)
count+=l;}

ostringstream ostr;
ostr<<count;
return ostr.str();
}

int main() {
vector <int> vector_int{2,3,4,5,6,7};
vector <double> vector_double{2.0,3.0,4.0,5.0,6.0,7.0};
vector <string> vector_string{"abc","bcd","cde"};

cout<<addall(vector_int)<<endl;
cout<<addall(vector_double)<<endl;
cout<<addall(vector_string)<<endl;

return 0;
}

//////////////////////////////////////////////////////////

output:-
27
27
891

The highly under-rated iostream library provides a much better option, in the form of ostringstream. This class provides a buffered stream, and returns us a std::string containing the information we have streamed to it. Because it is an iostream, we can pass any type into it so long as a stream handler exists for it. I'm not going to cover writing your own in this article, but it is really is very easy to do, and then you can stream any types you may create.

So the basic idea is that we create an ostringstream and then pass information into it, like this:


ostringstream strstrm;
strstrm << "This is how I pass in text, but I can pass in numbers as easily - "
<< 42 << endl;

We can then access the underlying string using the str() method, which we can chain to the strings c_str() method to get a const char * if desired. The