Untitled

#include <cmath>
#include <iostream>
#include <functional>
#include <vector>

using std::vector;
using std::function;

template <typename T, typename FunType>
vector<T> filter(const vector<T>& v, FunType p) {
    vector<T> filtered;
    int size = (int)v.size();
    for (int i = 0; i < size; i++) {
        if (p(v.at(i)) == true)
            filtered.push_back(v.at(i));
    }
    return filtered;
}

template <typename T, typename FunType1, typename FunType2>
vector<T> transfilt(vector<T>& v, FunType1 t, FunType2 p) {
    vector<T> transfiltered;
    int size = (int)v.size();
    for (int i = 0; i < size; i++) {
        v.at(i) = t(v.at(i));
        if (p(v.at(i)) == true)
            transfiltered.push_back(v.at(i));
    }
    return transfiltered;
}

template <typename T>
void printVec(const vector<T>& v) {
    int size = (int)v.size();
    for (int i = 0; i < size; i++) {
        if (i == 0)
            std::cout << "[ ";
        std::cout << v.at(i) << " ";
        if (i == (size - 1))
            std::cout << "] " << std::endl;
    }
}

int main() {
    vector<int> v{ 1, -3, 4, -2, 6, -8, 5 };
    printVec(v);
    vector<int> r = filter(v, [](int x) -> bool {
        if (x % 2 == 0)
            return true;
        else return false;
        });
    printVec(r);
    vector<int> s = filter(v, [](int x) -> bool {
            if (x > 0)
                return true;
            else return false;
        });
   printVec(s);

    vector<double> w{ 1.5, -3.1, 4.0, -2.0, 6.3 };
    printVec(w);
    double mn = -0.5, mx = 0.5;
    vector<double> d =
        transfilt(w, [](double x) -> double {
        return std::sin(x);
            }, [&](double x) -> bool {
                if (x >= mn && x <= mx)
                    return true;
                else return false;
            });
    printVec(w);
    printVec(d);
}