[clang-tidy] Potential memory leak?

`clang-tidy` on a project brought this to my attention:
```txt
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:375:17: error: Potential memory leak [clang-analyzer-cplusplus.NewDeleteLeaks,-warnings-as-errors]
m_sign = o.m_sign;
^
...
pravete_source.cpp:534:25: note: Calling copy assignment operator for 'number>, boost::multiprecision::et_on>'
my_private_include_path/include/boost/multiprecision/number.hpp:243:7: note: Calling copy assignment operator for 'cpp_int_backend<0, 0, boost::multiprecision::signed_magnitude, boost::multiprecision::unchecked, std::allocator>'
m_backend = e.m_backend;
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:1346:7: note: Calling 'cpp_int_base::assign'
this->assign(o);
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:369:7: note: Taking true branch
if (this != &o)
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:373:10: note: Calling 'cpp_int_base::resize'
resize(o.size(), o.size());
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:287:85: note: '?' condition is true
static const unsigned max_limbs = MaxBits / (CHAR_BIT * sizeof(limb_type)) + ((MaxBits % (CHAR_BIT * sizeof(limb_type))) ? 1 : 0);
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:289:11: note: Assuming 'new_size' is <= 'max_limbs'
if (new_size > max_limbs)
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:289:7: note: Taking false branch
if (new_size > max_limbs)
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:294:11: note: Assuming 'new_size' is > 'cap'
if (new_size > cap)
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:294:7: note: Taking true branch
if (new_size > cap)
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:298:28: note: Calling 'new_allocator::allocate'
limb_pointer pl = allocator().allocate(cap);
^
/usr/lib/gcc/x86_64-redhat-linux/7/../../../../include/c++/7/ext/new_allocator.h:101:2: note: Taking false branch
if (__n > this->max_size())
^
/usr/lib/gcc/x86_64-redhat-linux/7/../../../../include/c++/7/ext/new_allocator.h:111:27: note: Memory is allocated
return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp)));
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:298:28: note: Returned allocated memory
limb_pointer pl = allocator().allocate(cap);
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:300:15: note: Field 'm_internal' is false
if (!m_internal)
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:300:10: note: Taking true branch
if (!m_internal)
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:373:10: note: Returned allocated memory
resize(o.size(), o.size());
^
my_private_include_path/include/boost/multiprecision/cpp_int.hpp:375:17: note: Potential memory leak
m_sign = o.m_sign;
^
```
Is this a false positive ?