cppcoreguidelines-avoid-const-or-ref-data-members¶
This check warns when structs or classes have const-qualified or reference (lvalue or rvalue) data members. Having such members is rarely useful, and makes the class only copy-constructible but not copy-assignable.
Examples:
// Bad, const-qualified member
struct Const {
const int x;
}
// Good:
class Foo {
public:
int get() const { return x; }
private:
int x;
};
// Bad, lvalue reference member
struct Ref {
int& x;
};
// Good:
struct Foo {
int* x;
std::unique_ptr<int> x;
std::shared_ptr<int> x;
gsl::not_null<int> x;
};
// Bad, rvalue reference member
struct RefRef {
int&& x;
};
The check implements rule C.12 of C++ Core Guidelines.
Further reading: Data members: Never const.