error: ‘unique_ptr’ is not a member of ‘std’

Question

I guess it's pretty self explanatory - I can't seem to use C++11 features, even though I think I have everything set up properly - which likely means that I don't.

Here's my code:

#include <cstdlib> #include <iostream>  class Object {     private:         int value;      public:         Object(int val) {             value = val;         }          int get_val() {             return value;         }          void set_val(int val) {             value = val;         } };  int main() {      Object *obj = new Object(3);     std::unique_ptr<Object> smart_obj(new Object(5));     std::cout << obj->get_val() << std::endl;     return 0; } 

Here's my version of g++:

ubuntu@ubuntu:~/Desktop$ g++ --version g++ (Ubuntu/Linaro 4.7.3-2ubuntu1~12.04) 4.7.3 Copyright (C) 2012 Free Software Foundation, Inc. This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 

Here's how I'm compiling the code:

ubuntu@ubuntu:~/Desktop$ g++ main.cpp -o run --std=c++11 main.cpp: In function ‘int main()’: main.cpp:25:2: error: ‘unique_ptr’ is not a member of ‘std’ main.cpp:25:24: error: expected primary-expression before ‘>’ token main.cpp:25:49: error: ‘smart_obj’ was not declared in this scope 

Note that I've tried both -std=c++11 and -std=c++0x to no avail.

I'm running Ubuntu 12.04 LTS from a flash drive on an Intel x64 machine.

Answer 1

You need to include header where unique_ptr and shared_ptr are defined

#include <memory> 

As you already knew that you need to compile with c++11 flag

g++ main.cpp -o run -std=c++11 //                  ^