When a class or struct in C++ has compiler-provided or explicitly defaulted special member functions, then it is a trivial type. It occupies a contiguous memory area. It can have members with different access specifiers.
Trivial types have a trivial default constructor, trivial copy constructor, trivial copy assignment operator and trivial destructor. In each case, trivial means the constructor/ operator/ destructor is not user-provided and belongs to a class that has :
- No virtual functions or virtual base classes,
- No base classes with a corresponding non-trivial constructor/operator/destructor
- No data members of class type with a corresponding non-trivial constructor/operator/destructor
The following examples show trivial types :
Reference : https://learn.microsoft.com/en-us/previous-versions/mt767760(v=vs.140)?redirectedfrom=MSDN
