make_unique for c++11 @ hedgezzz的部落格

//http://scrupulousabstractions.tumblr.com/post/37576903218/cpp11style-no-new-delete
/* stephantl_make_unique.h
* Based on code by Stephan T. Lavavej at http://channel9.msdn.com/Series/
* C9-Lectures-Stephan-T-Lavavej-Core-C-/STLCCSeries6
*/

#ifndef STEPHANTL_MAKE_UNIQUE_H_
#define STEPHANTL_MAKE_UNIQUE_H_

#include <memory>
#include <utility>
#include <type_traits>

namespace fut_stl {
    namespace impl_fut_stl {
    template<typename T, typename ... Args>
            std::unique_ptr<T> make_unique_helper(std::false_type, Args&&... args) {
            return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
        }

        template<typename T, typename ... Args>
        std::unique_ptr<T> make_unique_helper(std::true_type, Args&&... args) {
            static_assert(std::extent<T>::value == 0,
                    "make_unique<T[N]>() is forbidden, please use make_unique<T[]>(),");
            typedef typename std::remove_extent<T>::type U;
            return std::unique_ptr<T>(new U[sizeof...(Args)]{std::forward<Args>(args)...});
        }
    }

    template<typename T, typename ... Args>
    std::unique_ptr<T> make_unique(Args&&... args) {
        return impl_fut_stl::make_unique_helper<T>(
            std::is_array<T>(),std::forward<Args>(args)... );
    }
}
#endif

#include <thread> 
#include <atomic> 
#include <stdio.h> 
#include <iostream> 
#include "stlav_make_unique.hpp" 
  
  
using namespace std; 
  
using LargeArray= array<int,10000>;  
  
unique_ptr<LargeArray> giveMeMyArray(){ 
    unique_ptr<LargeArray> myObj(new LargeArray() ); 
    myObj->at(3)=5; 
    return myObj; 
} 
  
unique_ptr<LargeArray> giveMeMyArray2(){ 
    unique_ptr<LargeArray> myObj = fut_stl::make_unique<LargeArray>(); 
    myObj->at(1)=1; 
    myObj->at(100)=100; 
    return myObj; 
} 
  
  
int main() 
{ 
    unique_ptr<LargeArray> ptr ; 
    ptr = giveMeMyArray() ; 
    for(int idx=0;idx<10000;idx++) 
    { 
        if(ptr->at(idx) >0) 
            cout << "idx=" << idx << " " << ptr->at(idx) << endl ; 
    } 
    unique_ptr<LargeArray> ptr2 ; 
    ptr2 = giveMeMyArray2() ; 
    for(int idx=0;idx<10000;idx++) 
    { 
        if(ptr2->at(idx) >0) 
            cout << "idx=" << idx << " " << ptr2->at(idx) << endl ; 
    } 
      
}
 