*** Changes in GCC 2.95: * Messages about non-conformant code that we can still handle ("pedwarns") are now errors by default, rather than warnings. This can be reverted with -fpermissive, and is overridden by -pedantic or -pedantic-errors. * String constants are now of type `const char[n]', rather than `char[n]'. This can be reverted with -fno-const-strings. * References to functions are now supported. * Lookup of class members during class definition now works in all cases. * In overload resolution, type conversion operators are now properly treated as always coming from the most derived class. * C99-style restricted pointers are supported, using the `__restrict' keyword. * You can now use -fno-implicit-inline-templates to suppress writing out implicit instantiations of inline templates. Normally we do write them out, even with -fno-implicit-templates, so that optimization doesn't affect which instantiations are needed. * -fstrict-prototype now also suppresses implicit declarations. * Many obsolete options have been removed: -fall-virtual, -fmemoize-lookups, -fsave-memoized, +e?, -fenum-int-equivalence, -fno-nonnull-objects. * Unused virtual functions can be discarded on some targets by specifying -ffunction-sections -fvtable-gc to the compiler and --gc-sections to the linker. Unfortunately, this only works on Linux if you're linking statically. * Lots of bugs stomped. *** Changes in EGCS 1.1: * Namespaces are fully supported. The library has not yet been converted to use namespace std, however, and the old std-faking code is still on by default. To turn it off, you can use -fhonor-std. * Massive template improvements: + member template classes are supported. + template friends are supported. + template template parameters are supported. + local classes in templates are supported. + lots of bugs fixed. * operator new now throws bad_alloc where appropriate. * Exception handling is now thread safe, and supports nested exceptions and placement delete. Exception handling overhead on x86 is much lower with GNU as 2.9. * protected virtual inheritance is now supported. * Loops are optimized better; we now move the test to the end in most cases, like the C front end does. * For class D derived from B which has a member 'int i', &D::i is now of type 'int B::*' instead of 'int D::*'. * An _experimental_ new ABI for g++ can be turned on with -fnew-abi. The current features of this are more efficient allocation of base classes (including the empty base optimization), and more compact mangling of C++ symbol names (which can be turned on separately with -fsquangle). This ABI is subject to change without notice, so don't use it for anything that you don't want to rebuild with every release of the compiler. As with all ABI-changing flags, this flag is for experts only, as all code (including the library code in libgcc and libstdc++) must be compiled with the same ABI.
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