C++11 STL

gistfile1.cpp

#include <iostream>
#include <vector>
#include <functional>
#include <initializer_list>
#include <string>

using namespace std;

template <typename TT>
class RArray : protected vector<TT>
{
public:
    RArray() {}
    RArray( const initializer_list<TT> & val ) : vector<TT>(val) {}
    
    void push ( const TT & value ) {
        vector<TT>::push_back(value);
    }
    
    void each ( const function<void (const TT &)> & fn ) const {
        for ( const auto & v : *this )
            fn ( v );
    }

    template <typename TR>
    RArray<TR> map ( const function<TR (const TT & )> &fn ) const {
        RArray<TR> res;
        for ( const auto & v : *this )
            res.push( fn(v) );
        return res;
    }
    
    template <typename TR>
    TR fold ( const TR & zero, const function<TR (const TR &, const TT &)> & fn ) const {
        TR res = zero;
        for ( const auto & v : *this )
            res = fn(res, v);
        return res;
    }
};

template <typename FU, typename T>
void each(const FU & fn, const T& value)
{
    value.each(fn);
}

template <typename FU, typename U, typename... T>
void each(const FU & fn, const U& head, const T&... tail)
{
    head.each(fn);
    each(fn, tail...);
}

int main(int argc, const char * argv[])
{
    RArray<int> foo = {1, 2, 3};
    
    foo.each([&](int t){
        cout << t << " ";
    });
    cout << endl;
    
    auto bar = foo.map<int>([&](int t) {
        return t + 3;
    });
    
    auto res = bar.fold<string>( "", [&](const string & s, int t){
        return s + to_string(t) + " ";
    });
    cout << res << endl;
    
    each ( [&](int t){
        cout << t << " ";
    }, foo, bar );
    cout << endl;
    
    return 0;
}