std::shared_ptr..unable to resolve identifier

Question

0.00/5 (No votes)

See more:

I am trying my hands on the smart pointers in c++. I have included <memory> header file in my code but my code is giving me error saying "unable to resolve identifier" on the line

std::shared_ptr<person> p(new Person("Scott", 25));

Where Person is a class that i have created in my code.

Please can anyone help..??

Posted 10-Apr-13 2:22am

AsthaS

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

CPallini · Answer 1 · 2013-04-10T02:56:00

Solution 2

Quote:
std::shared_ptr p(new Person("Scott", 25));

It should be

C++

std::shared_ptr<Person> p(new Person("Scott", 25));

shouldn't it?

The following code compiles (and runs) fine (Visual C++ Express 2010):

C++

#include <memory>
#include <iostream>
class Person
{
  int age;
  const char * name;
public:
  Person(const char * name, int age):name(name), age(age){}
    void show(){std::cout << name << " " << age << std::endl;}
};


int main()
{
  std::shared_ptr<Person> p(new Person("Scott", 25));
    p->show();
}

Posted 10-Apr-13 2:56am

CPallini

Updated 10-Apr-13 23:24pm

v2

Comments

AsthaS 11-Apr-13 0:50am

Yess..my mistake. it should be the way u wrote it...but still the problem of undefined reference persists.. :(

Stefan_Lang 11-Apr-13 5:12am

There are only two identifiers on that line that could be undefined: std::shared_ptr and Person. Make sure you included the appropriate header files.

AsthaS 11-Apr-13 5:19am

have included #include< memory >. Is there some other header which i need to include for shared_ptr.??

AsthaS 11-Apr-13 5:32am

I am using netbeans 7.3 with cygwin to run this code. Hope this is not the root of error.

CPallini 11-Apr-13 5:40am

Could you please try the little code I posted?

AsthaS 11-Apr-13 5:45am

I have tried the code. But the same error--Unable to resolve identifier shared_ptr-- But it works fine if i change shared_ptr with auto_ptr.. :(

CPallini 11-Apr-13 6:11am

Then as Orjan Westin suggests, you have an old compiler. Either try his solution or update the compiler.

Orjan Westin · Answer 2 · 2013-04-10T23:58:00

std::shared_ptr is a C++11 addition. (It was in Technical Report 1, published in 2007. VC++ 2010 included it in <memory> since it was well known it would become part of the standard, but strictly speaking it should have been left in the tr1 namespace.)

If your compiler doesn't support C++11, you could try to use:

<br />
#include <tr1/memory><br />
...<br />
std::tr1::shared_ptr<Person&gr; p(new Person("Scott", 25));<br />

Otherwise, you can get it from the Boost libraries, which is where it was developed and tested before it's inclusion in C++11.