Closures (2)

cplusplus.cpp

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

int main()
{
    std::vector<std::function<int (int)>> l;
    for(int i = 0; i < 10; ++i)
        l.push_back([=](int x) mutable { return i += x; });
    std::cout << l[2](3) << ", ";       // 5
    std::cout << l[2](4) << ", ";       // 9
    std::cout << l[4](2) << std::endl;  // 6
    return 0;
}

go.go

package main

import (  
    "fmt"
    "runtime"
    "sync"
)

func main() {  
    runtime.GOMAXPROCS(runtime.NumCPU())

    var wg sync.WaitGroup
    for i := 0; i < 10; i++ {
        wg.Add(1)
        go func() {
            fmt.Printf("%d ", i)
            wg.Done()
        }()
    }

    wg.Wait() // 10 10 10 10 10 10 10 10 10 10  
}

lua.lua

l = {}
for i = 0, 10 do
    l[i] = function(x)
        i = i + x
        return i
    end
end
print(l[2](3)) -- 5
print(l[2](4)) -- 9
print(l[4](2)) -- 6

python.py

l= []
for i in xrange(10):
    def anonym(x, i=i):
        i += x
        return i
    l.append(anonym)

print l[2](3) # 5
print l[2](4) # 6
print l[4](2) # 6