Class template implementation with multiple vectors - c++

Question

I'm creating a program that reads in a data file into a vector and then shows the minimum and maximum information for the vector. I also have to use a class template for finding the minimum and maximum. I'm wondering if there is a way I can reference ANY vector without having to specifically label the two vectors I want to use. In my code below, I have to state vector v1 to get my template to do the minimum and maximum. Is it possible to make this template for any vector?
//Nicholas Stafford
//COP2535.0M1
//Read in text file into multiple vectors and display maximum and minimum integers/strings.
#include <iostream>
#include <string>
#include <vector>
#include <fstream>
#include <algorithm>
using namespace std;
//Template code area
template <class T>
T min(vector<T> v1)
{
T lowest = v1[0];
for (int k = 1; k < 10; k++)
{
if (v1[k] < lowest)
lowest = v1[k];
}
return lowest;
}
template <class T>
T max(vector<T> v1)
{
T highest = v1[0];
for (int k = 1; k < 10; k++)
{
if (v1[k] > highest)
highest = v1[k];
}
return highest;
}
int main() {
//Number of items in the file
const int size = 10;
//Vector and file stream declaration
ifstream inFile;
string j; //String for words in data file
vector<int> v1(size); //Vector for integers
vector<string> v2(size); //Vector for strings
//Open data file
inFile.open("minmax.txt");
//Loop to place values into vector
if (inFile)
{
for (int i = 0; i < size; i++)
{
inFile >> v1[i];
v1.push_back(v1[i]); //Add element to vector
}
cout << "The minimum number in the vector is " << min(v1) << endl;
cout << "The maximum number in the vector is " << max(v1) << endl;
}
else
{
cout << "The file could not be opened." << endl;
}
}

Answer 1

You're having a simple misunderstanding. Just because the function parameter to your min and max is v1 doesn't mean the only thing you can call it with is something called v1. Actually, it will be a local copy of the vector passed in, locally named v1.
#include <vector>
#include <iostream>
template<typename T>
size_t sizeit(std::vector<T> v) // try changing to v1, v2 and vx
{
return v.size(); // change to match
}
int main() {
std::vector<int> v1 { 1, 2, 3, 4, 5 };
std::vector<float> v2 { 1., 2., 3. };
std::cout << "v1 size = " << sizeit(v1) << "\n";
std::cout << "v2 size = " << sizeit(v2) << "\n";
}
Live demo: http://ideone.com/cK13bR