Creating unique_ptr of non plain data in C++

Question

The ptr constructors works with plain data but fails with objects:

#include <string>
#include <memory>

struct MyClass{};

int main() {

    std::unique_ptr<int> ptr(new int(5));
    std::unique_ptr<std::string> ptr1(new std::string("string")); //function 'ptr1' could not be resolved.
    std::unique_ptr<MyClass> ptr2(new MyClass); //unction 'ptr2' could not be resolved.
    return 0;
}

why?

My g++ version is (Ubuntu/Linaro 4.7.3-2ubuntu1~12.04) 4.7.3

Answer 1

You mentioned it fails in eclipse, so you might try disabling eclipse internal code validation, by:

going to project properties -> C/C++ General -> Code Analysis -> check Use project settings and then in Syntax and Semantic Errors uncheck all Error lines.

You might need to delete previous errors from output, by simply selecting them and deleting.

Actually there is one line with pattern 'Function ''{0}'' could not be resolved', normally g++ would not give you such error (I at least never seen such)

Answer 2

Actually, these initializations work just fine - the following code compiles fine e.g. with g++ 4.8.2:

#include <memory>
#include <string>

struct MyClass { };

int main()
{
    std::unique_ptr<int> ptr(new int(5));
    std::unique_ptr<std::string> ptr1(new std::string("string"));
    std::unique_ptr<MyClass> ptr2(new MyClass);
}