7.13. Backwards Compatibility
7.13 Backwards Compatibility
Now that there is a definitive ISO standard C++, G++ has a specification to adhere to. The C++ language evolved over time, and features that used to be acceptable in previous drafts of the standard, such as the ARM [Annotated C++ Reference Manual], are no longer accepted. In order to allow compilation of C++ written to such drafts, G++ contains some backwards compatibilities. All such backwards compatibility features are liable to disappear in future versions of G++. They should be considered deprecated. See Deprecated Features.
For scope
- If a variable is declared at for scope, it used to remain in scope until the end of the scope that contained the for statement (rather than just within the for scope). G++ retains this, but issues a warning, if such a variable is accessed outside the