Category 

Type Trait Functions 

Syntax 

bool __has_trivial_copy_constructor ( typename T ) 

Returns true if and only if T has a trivial default constructor. 

Error if T is an incomplete type. 

False (but well-formed) if a class type does not have a default constructor 

The definition (from Section 20.4.4.3 of the Working Draft) notes has a type T has a trivial copy constructor if it is in the list::

• a scalartype (or array thereof)
• a reference type (or array thereof)
• an array of class type with trivial destructor
• a class type with a trivial copy constructor (12.8)

According to Section 12.8 p6 of the Working Draft: 

A copy constructor for class X is trivial if:

• It is not user provided (see Section 8.4)
• class X has no virtual functions
• class X has no virtual base classes
• each direct base class of X has a trivial copy constructor.
• for all the non-static data members of X that are of class type (or array thereof), each such class type has a trivial copy constructor;.

A copy constructor is not user provided if it is implicitly declared, or defined inline as = default; 

Ox interaction false if the default constructor is defined as deleted. 

Ox interactionwith default function definitions.