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

Could you provide minimal failing example, like the one in Mr.C64's answer? — mike.dld, Feb 26 '14 at 17:57
Works fine with :g++ -std=c++0x CppTest.cpp But fails in Eclipse. — Sashko Lykhenko, Feb 26 '14 at 18:13
http://stackoverflow.com/search?q=eclipse+could+not+be+resolved — mike.dld, Feb 26 '14 at 18:16
This is line to compile in Eclipse: g++ -D__GXX_EXPERIMENTAL_CXX0X__ -O0 -g3 -Wall -c -fmessage-length=0 -std=c++0x -MMD -MP -MF"src/CppTest.d" -MT"src/CppTest.d" -o "src/CppTest.o" "../src/CppTest.cpp" — Sashko Lykhenko, Feb 26 '14 at 18:16
possible duplicate of [Eclipse - Method NewStringUTF() could not be resolved](http://stackoverflow.com/questions/15899813/eclipse-method-newstringutf-could-not-be-resolved) — mike.dld, Feb 26 '14 at 18:23

score 1 · Answer 1 · answered Feb 26 '14 at 17:53

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);
}

score 0 · Accepted Answer · answered Feb 26 '14 at 18:19

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)

Creating unique_ptr of non plain data in C++

2 Answers2