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| + | |||
| + | <code> | ||
| + | |||
| + | make -k main && cat main.cpp && ./main | ||
| + | g++ main.cpp -o main | ||
| + | /* #ident "$Id: main.cpp$" | ||
| + | * @author: rzr@gna.org - rev: $Author: rzr$ | ||
| + | * Copyright: See README file that comes with this distribution | ||
| + | *****************************************************************************/ | ||
| + | |||
| + | #include <cstdio> | ||
| + | #include <cstdlib> | ||
| + | #include <cstring> | ||
| + | #include <iostream> | ||
| + | #include <cassert> | ||
| + | |||
| + | #define LOG() \ | ||
| + | std::cout \ | ||
| + | << __FILE__ << ":" << __LINE__ << ": log: " << __PRETTY_FUNCTION__ << std::endl | ||
| + | |||
| + | class Main | ||
| + | { | ||
| + | public: | ||
| + | |||
| + | Main() { | ||
| + | LOG(); | ||
| + | ptr_ = new char[1]; | ||
| + | } | ||
| + | |||
| + | virtual ~Main() { | ||
| + | LOG(); | ||
| + | delete( ptr_); | ||
| + | } | ||
| + | |||
| + | public: | ||
| + | |||
| + | inline char * getPtr() const { | ||
| + | LOG(); | ||
| + | return(getPtrNew()); | ||
| + | } | ||
| + | |||
| + | ///TODO: express: char const * const getPtr() const | ||
| + | inline char const * const getPtr(bool isconst/*=true*/) const { | ||
| + | LOG(); | ||
| + | assert(isconst == true); | ||
| + | return( getPtrConst() ); | ||
| + | } | ||
| + | |||
| + | public: //or private as you want | ||
| + | |||
| + | char * getPtrNew() const { | ||
| + | LOG(); | ||
| + | return(strdup(ptr_)); | ||
| + | } | ||
| + | |||
| + | char const * const getPtrConst() const | ||
| + | { | ||
| + | LOG(); | ||
| + | return(ptr_); | ||
| + | } | ||
| + | |||
| + | private: | ||
| + | char * ptr_; | ||
| + | |||
| + | }; | ||
| + | |||
| + | |||
| + | int main() | ||
| + | { | ||
| + | Main const main; | ||
| + | { | ||
| + | LOG(); | ||
| + | char* pnew = main.getPtr(); | ||
| + | delete(pnew); | ||
| + | } | ||
| + | { | ||
| + | LOG(); | ||
| + | Main const main; | ||
| + | char const * const pconst = main.getPtr(true); | ||
| + | // no need to delete , main's destructor will do | ||
| + | } | ||
| + | { | ||
| + | LOG(); | ||
| + | char const */* const*/ pconst = main.getPtr(true); | ||
| + | pconst = 0; // TODO: should be avoid if prev line use const.. | ||
| + | LOG(); | ||
| + | char const * const pnew = main.getPtr(); // TODO: delete const ? | ||
| + | delete(pnew); | ||
| + | } | ||
| + | return 0; | ||
| + | } | ||
| + | |||
| + | /* | ||
| + | |||
| + | make -k main && cat main.cpp && ./main | ||
| + | |||
| + | */ | ||
| + | |||
| + | //#eof "$Id:$" | ||
| + | |||
| + | main.cpp:21: log: Main::Main() | ||
| + | main.cpp:67: log: int main() | ||
| + | main.cpp:33: log: char* Main::getPtr() const | ||
| + | main.cpp:47: log: char* Main::getPtrNew() const | ||
| + | main.cpp:72: log: int main() | ||
| + | main.cpp:21: log: Main::Main() | ||
| + | main.cpp:39: log: const char* const Main::getPtr(bool) const | ||
| + | main.cpp:53: log: const char* const Main::getPtrConst() const | ||
| + | main.cpp:26: log: virtual Main::~Main() | ||
| + | main.cpp:78: log: int main() | ||
| + | main.cpp:39: log: const char* const Main::getPtr(bool) const | ||
| + | main.cpp:53: log: const char* const Main::getPtrConst() const | ||
| + | main.cpp:81: log: int main() | ||
| + | main.cpp:33: log: char* Main::getPtr() const | ||
| + | main.cpp:47: log: char* Main::getPtrNew() const | ||
| + | main.cpp:26: log: virtual Main::~Main() | ||
| + | |||
| + | </code> | ||
| + | |||
| + | |||
| + | One track to avoid the cast : | ||
| + | |||
| + | <code> | ||
| + | template<typename T> | ||
| + | T getPtr() { | ||
| + | return (0); | ||
| + | } | ||
| + | </code> | ||
| + | |||
| + | |||
| + | ==== MISC ==== | ||
| + | |||
| + | http://en.wikipedia.org/wiki/Const-correctness#Loopholes_to_const-correctness | ||
| + | |||
| + | error: assignment of read-only reference | ||
| + | |||
| + | |||