Question

i’m using gcc 4.6.2.

I’m trying to push_back in a vector shared_ptr’s.

But gcc gives me everytime an error.

Here my codelines:

std::vector< std::tr1::shared_ptr<Process> > procs;
std::string line;
while (getline(file, line) && line.find(JobMask) != std::string::npos)
{
    std::string procName                      = line.substr(line.find(JobMask) + JobMask.size());
    std::vector<Instruction> procInstructions = extractProgram(file);
    std::queue<int>          procInputs       = extractInputs(file);

    if (!procInstructions.empty())
        procs.push_back(std::make_shared<Process>(Process(procName, procInputs, procInstructions))); //line 51
}
return procs;

The Error my gcc is giving is:

Process.cpp: In static member function 'static std::vector<std::tr1::shared_ptr<RMMIX::Process> > RMMIX::Process::createProcesses(const string&)':

Process.cpp:51:95: error: no matching function for call to 'std::vector<std::tr1::shared_ptr<RMMIX::Process> >::push_back(std::shared_ptr<RMMIX::Process>)'

Process.cpp:51:95: note: candidates are:
/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.2/include/g++-v4/bits/stl_vector.h:826:7: note: void std::vector<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = std::tr1::shared_ptr<RMMIX::Process>, _Alloc = std::allocator<std::tr1::shared_ptr<RMMIX::Process> >, std::vector<_Tp, _Alloc>::value_type = std::tr1::shared_ptr<RMMIX::Process>]
/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.2/include/g++-v4/bits/stl_vector.h:826:7: note:   no known conversion for argument 1 from 'std::shared_ptr<RMMIX::Process>' to 'const value_type& {aka const std::tr1::shared_ptr<RMMIX::Process>&}'
/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.2/include/g++-v4/bits/stl_vector.h:839:7: note: void std::vector<_Tp, _Alloc>::push_back(std::vector<_Tp, _Alloc>::value_type&&) [with _Tp = std::tr1::shared_ptr<RMMIX::Process>, _Alloc = std::allocator<std::tr1::shared_ptr<RMMIX::Process> >, std::vector<_Tp, _Alloc>::value_type = std::tr1::shared_ptr<RMMIX::Process>]
/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.2/include/g++-v4/bits/stl_vector.h:839:7: note:   no known conversion for argument 1 from 'std::shared_ptr<RMMIX::Process>' to 'std::vector<std::tr1::shared_ptr<RMMIX::Process> >::value_type&& {aka std::tr1::shared_ptr<RMMIX::Process>&&}'

In my eyes the error say’s, that std::make_shared create a std::shared_ptr.
But in gcc shared_ptr is in the namespace std::tr1.
How could i fix it?

Answer 1

If I understand correctly, make_shared is new in C++11 and is in namespace std, but it is only available if you compile with -std=gnu++0x or similar. But if you do that, then shared_ptr is also in std.

The problem is that there is another version of shared_ptr in std::tr1, but in C++11 mode you should not use it: it should be considered deprecated.

Your solution is simply to remove every use of tr1 and use the full C++11 version of these classes.