QubitRegister<Type>::QubitRegister(new_num_qubits, Type *state) doesnt work correctly

[mbuchberger1967]

Describe the bug

template <class Type>
QubitRegister<Type>::QubitRegister(std::size_t new_num_qubits, Type *state, 
                                   std::size_t tmp_spacesize_)
{
  imported_state = true;
  Initialize(new_num_qubits, tmp_spacesize_);

  this->state = state;
}

has two problems:

1. it doesn't initialize all needed class variables, e.g. "specialized", so this flag is sometimes true, sometimes false
2. it doesn't work if USE_MM_ALLOC is not defined -> memory crash

To Reproduce
Steps to reproduce the behavior:
Use the ctor and initialize the statevector with a prepared memory pointer, undef MM_USE_MALLOC

Fixes

1. init all class variables in the declaration
2. add code for undef USE_MM_MALLOC with a specialized AlignedAllocator to transport the memory block into state_storage

See my PR #57

[giangiac]

Hi @mbuchberger1967 , thanks for pointing out this issue.
I will give a look to your solution.

[mbuchberger1967]

Hi @giangiac
we have this fix in our fork and it is working fine.
you really should give it a try....
BR
Markus

[giangiac]

Hi @mbuchberger1967
Thanks for the reminder.
I'll give a look at pull request #57