C++ concepts: CopyInsertable
From cppreference.com
                    
                                        
                    
                    
                                                            
                    Specifies that an instance of the type can be copy-constructed in-place, in uninitialized storage.
[edit] Requirements
The type T is CopyInsertable into the container X if, given
| A | the allocator type defined as X::allocator_type | 
| m | the lvalue of type Aobtained fromX::get_allocator() | 
| p | the pointer of type T*prepared by the container | 
| v | expression of type T, provided as the argument to push_back(), etc | 
-  The type TsatisfiesMoveInsertable, and the following expression is well-formed:
   std::allocator_traits<A>::construct(m, p, v);
And after evaluation, the value of *p is equivalent to the value of v. The value of v is unchanged.
[edit] Notes
If A is std::allocator<T>, then this will call placement-new, as by ::new((void*)p) T(v)


