Condition '!ptr' is always true when calling std::unique_ptr::reset

[ttressieres]

With the following code, I receive a condition is always true at line 17

#include <memory>

int * allocate(int * in)
{
    if (!in)
        return new int(2);
    delete in;
    return nullptr;
}

int main(int, char **)
{
    std::unique_ptr<int> ptr(allocate(nullptr));
    if (!ptr)
        return -1;
    ptr.reset(allocate(ptr.release()));
    if (!ptr)
        return -1;
    return 0;
}

cppcheck.exe --enable=all --template=vs --library=std.cfg --library=windows.cfg -DOS_NT -DWIN32 -D_WIN32 -DNDEBUG -D_cppcheck --inline-suppr test.cpp
Checking test.cpp ...
Checking test.cpp: OS_NT=1;WIN32=1;_WIN32=1;NDEBUG=1;_cppcheck=1...
test.cpp(17): style: Condition '!ptr' is always true
nofile(0): information: Cppcheck cannot find all the include files (use --check-config for details)

It's new with version 1.88

[Paul Fultz]

This is most likely because we do not recognize reset or release as methods that can change the variable. I wonder if its as easy as updating std.cfg about these methods.

[versat]

The only configuration regarding unique_ptr in std.cfg is currently:

  <smart-pointer class-name="std::unique_ptr"/>

I guess that Cppcheck should assume that variables are changed if the function is unknown/not configured. So IMHO this looks like an issue in Cppcheck.