gcc: Deprecated Features

1 
1 7.11 Deprecated Features
1 ========================
1 
1 In the past, the GNU C++ compiler was extended to experiment with new
1 features, at a time when the C++ language was still evolving.  Now that
1 the C++ standard is complete, some of those features are superseded by
1 superior alternatives.  Using the old features might cause a warning in
1 some cases that the feature will be dropped in the future.  In other
1 cases, the feature might be gone already.
1 
1  While the list below is not exhaustive, it documents some of the
1 options that are now deprecated or have been removed:
1 
1 '-fno-for-scope'
1 '-ffriend-injection'
1      These two options provide compatibility with pre-standard C++.
1      ⇒Backwards Compatibility.
1 
1  G++ allows a virtual function returning 'void *' to be overridden by
1 one returning a different pointer type.  This extension to the covariant
1 return type rules is now deprecated and will be removed from a future
1 version.
1 
1  The use of default arguments in function pointers, function typedefs
1 and other places where they are not permitted by the standard is
1 deprecated and will be removed from a future version of G++.
1 
1  G++ allows floating-point literals to appear in integral constant
1 expressions, e.g. ' enum E { e = int(2.2 * 3.7) } ' This extension is
1 deprecated and will be removed from a future version.
1 
1  G++ allows static data members of const floating-point type to be
1 declared with an initializer in a class definition.  The standard only
1 allows initializers for static members of const integral types and const
1 enumeration types so this extension has been deprecated and will be
1 removed from a future version.
1 
1  G++ allows attributes to follow a parenthesized direct initializer,
1 e.g. ' int f (0) __attribute__ ((something)); ' This extension has been
1 ignored since G++ 3.3 and is deprecated.
1 
1  G++ allows anonymous structs and unions to have members that are not
1 public non-static data members (i.e. fields).  These extensions are
1 deprecated.
1