Deprecated Features#
In the past, the GNU C++ compiler was extended to experiment with new features, at a time when the C++ language was still evolving. Now that the C++ standard is complete, some of those features are superseded by superior alternatives. Using the old features might cause a warning in some cases that the feature will be dropped in the future. In other cases, the feature might be gone already.
G++ allows a virtual function returning void *
to be overridden
by one returning a different pointer type. This extension to the
covariant return type rules is now deprecated and will be removed from a
future version.
The use of default arguments in function pointers, function typedefs and other places where they are not permitted by the standard is deprecated and will be removed from a future version of G++.
G++ allows floating-point literals to appear in integral constant expressions,
e.g. enum E e = int(2.2 * 3.7)
This extension is deprecated and will be removed from a future version.
G++ allows static data members of const floating-point type to be declared with an initializer in a class definition. The standard only allows initializers for static members of const integral types and const enumeration types so this extension has been deprecated and will be removed from a future version.
G++ allows attributes to follow a parenthesized direct initializer,
e.g. int f (0) __attribute__ ((something));
This extension
has been ignored since G++ 3.3 and is deprecated.
G++ allows anonymous structs and unions to have members that are not public non-static data members (i.e. fields). These extensions are deprecated.