C++ concepts: StandardLayoutType
From cppreference.com
Specifies that a type is standard layout type. Standard layout types are useful for communicating with code written in other programming languages.
Note, that the standard doesn't define a named requirement or concept with this name. This is a type category defined by the core language. It is included here as concept only for consistency.
[edit] Requirements
- All non-static data members have the same access control
- Has no virtual functions or virtual base classes
- All non-static data members and base classes are themselves standard layout types
- Has no two base class subobjects of the same type
struct Q {}; struct S : Q { }; struct T : Q { }; struct U : S, T { }; // not a standard-layout class
- Has all non-static data members declared in the same class (either all in the derived or all in some base)
struct B { int i; }; // standard-layout class struct C : B { }; // standard-layout class struct D : C { }; // standard-layout class struct E : D { char : 4; }; // not a standard-layout class
- None of the base class subobjects has the same type as
-
- for non-union types, as the first non-static data member (see empty base optimization), and, recursively, the first non-static data member of that data member if it has non-union class type, or all non-static data members of that data member if it has union type, etc.
- for union types, as any non-static data members, and, recursively, the first non-static data member of every member of non-union class type and all non-static data members of all members of union type, etc.
[edit] Properties
See Standard layout.
[edit] See also
| (C++11)
|
checks if a type is standard-layout type (class template) |