【C++】ポインターのスコープをチェックする【修正済】 ref: http://qiita.com/atmarksharp/items/db1afac2ba4c64f88e4d

file0.cpp

#include <iostream>
#include <string>

#define bold "\e[1;30m"
#define red "\e[0;31m"
#define green "\e[0;32m"
#define cyan "\e[0;36m"
#define reset "\e[0m"

using namespace std;

// Testクラス
class Test{
public:
    Test()
    {
        cout << red << "<< Test: created >>" << reset << endl;
    }

    ~Test(){
        cout << green << "<< ~Test: deleted >>" << green << endl;
    }
};

// ログを出力
void log(string s){
    cout << s << endl;
}

// ポインターがNULLならNULL、それ以外ならOKと表示
// 出力： 変数名(スコープLv): [OK or NULL]
void exists(void* t,string name,string scope){
    if(t){
        log(name + "(" + scope + "): OK");
    }else{
        log(name + "(" + scope + "): NULL");
    }
}

//===========================================

// テストを実行
void scope_check1(){
    cout << cyan << "[Scope Check 1]" << reset << endl << endl;

    // コンパイルエラーが起こらないようにする
    void* a(NULL);
    void* b(NULL);
    void* c(NULL);

    exists(a,"a","0: before"); // NULL
    exists(b,"b","0: before"); // NULL
    exists(c,"c","0: before"); // NULL
    log("");
    {   
        void* a(new Test);
        exists(a,"a","1: before"); // OK
        log("");
        {
            void* b(new Test);
            exists(a,"a","2: before"); // OK
            exists(b,"b","2: before"); // OK
            log("");
            {
                void* c(new Test);
                exists(a,"a","3"); // OK
                exists(b,"b","3"); // OK
                exists(c,"c","3"); // OK
                log("");
            }
            // ローカル変数"c"はスコープを外れている
            exists(a,"a","2: after"); // OK
            exists(b,"b","2: after"); // OK
            exists(c,"c","2: after"); // NULL
            log("");
        }
        // ローカル変数"b,c"はスコープを外れている
        exists(a,"a","1: after"); // OK
        exists(b,"b","1: after"); // NULL
        exists(c,"c","1: after"); // NULL
        log("");
    }
    // ローカル変数"a,b,c"はスコープを外れている
    exists(a,"a","0: after"); // NULL
    exists(b,"b","0: after"); // NULL
    exists(c,"c","0: after"); // NULL
}

int main(){
    log("");
    {
        scope_check1();
    }
    log("");

    return 0;
}

file1.cpp

#include <iostream>
#include <string>
#include <memory>

#define bold "\e[1;30m"
#define red "\e[0;31m"
#define green "\e[0;32m"
#define cyan "\e[0;36m"
#define reset "\e[0m"

using namespace std;

class Test{
public:
    Test()
    {
        cout << red << "<< Test: created >>" << reset << endl;
    }

    ~Test(){
        cout << green << "<< ~Test: deleted >>" << green << endl;
    }
};

void log(string s){
    cout << s << endl;
}

void exists(void* t,string name,string scope){
    if(t){
        log(name + "(" + scope + "): OK");
    }else{
        log(name + "(" + scope + "): NULL");
    }
}

//===========================================

class ScopeCheck2{
public:
    void* a;
    void* b;
    void* c;

    ScopeCheck2():
        a(NULL),
        b(NULL),
        c(NULL)
    {
        cout << cyan << "[Scope Check 2]" << reset << endl << endl;
        exists(a,"a","0: before"); // NULL
        exists(b,"b","0: before"); // NULL
        exists(c,"c","0: before"); // NULL
        log("");
        {   
            void* a(new Test);
            exists(a,"a","1: before"); // OK
            log("");

            this->a = a; // <<< COPY REFERENCE >>>
            {
                void* b(new Test);
                exists(a,"a","2: before"); // OK
                exists(b,"b","2: before"); // OK
                log("");

                this->b = b; // <<< COPY REFERENCE >>>
                {
                    void* c(new Test);
                    exists(a,"a","3"); // OK
                    exists(b,"b","3"); // OK
                    exists(c,"c","3"); // OK
                    log("");

                    this->c = c; // <<< COPY REFERENCE >>>
                }
                exists(a,"a","2: after"); // OK
                exists(b,"b","2: after"); // OK
                exists(c,"c","2: after"); // NULL -> OK
                log("");
            }
            exists(a,"a","1: after"); // OK
            exists(b,"b","1: after"); // NULL -> OK
            exists(c,"c","1: after"); // NULL -> OK
            log("");
        }
        exists(a,"a","0: after"); // NULL -> OK
        exists(b,"b","0: after"); // NULL -> OK
        exists(c,"c","0: after"); // NULL -> OK
    }
};

int main(){
    log("");
    {
        ScopeCheck2 sct;
    }
    log("");

    return 0;
}

file2.cpp

#include <iostream>
#include <string>
#include <memory>

#define bold "\e[1;30m"
#define red "\e[0;31m"
#define green "\e[0;32m"
#define cyan "\e[0;36m"
#define reset "\e[0m"

using namespace std;

class Test{
public:
    Test()
    {
        cout << red << "<< Test: created >>" << reset << endl;
    }

    ~Test(){
        cout << green << "<< ~Test: deleted >>" << reset << endl;
    }
};

void log(string s){
    cout << s << endl;
}

void exists(shared_ptr<Test> t,string name,string scope){
    if(t){
        log(name + "(" + scope + "): OK");
    }else{
        log(name + "(" + scope + "): NULL");
    }
}

//===========================================

class ScopeCheck3{
public:
    shared_ptr<Test> a;
    shared_ptr<Test> b;
    shared_ptr<Test> c;

    ScopeCheck3():
        a(NULL),
        b(NULL),
        c(NULL)
    {
        cout << cyan << "[Scope Check 3]" << reset << endl << endl;
        exists(a,"a","0: before"); // NULL
        exists(b,"b","0: before"); // NULL
        exists(c,"c","0: before"); // NULL
        log("");
        {   
            shared_ptr<Test> a(new Test);
            exists(a,"a","1: before"); // OK
            log("");

            this->a = a; // <<< COPY REFERENCE >>>
            {
                shared_ptr<Test> b(new Test);
                exists(a,"a","2: before"); // OK
                exists(b,"b","2: before"); // OK
                log("");

                this->b = b; // <<< COPY REFERENCE >>>
                {
                    shared_ptr<Test> c(new Test);
                    exists(a,"a","3"); // OK
                    exists(b,"b","3"); // OK
                    exists(c,"c","3"); // OK
                    log("");

                    this->c = c; // <<< COPY REFERENCE >>>
                }
                exists(a,"a","2: after"); // OK
                exists(b,"b","2: after"); // OK
                exists(c,"c","2: after"); // NULL -> OK
                log("");
            }
            exists(a,"a","1: after"); // OK
            exists(b,"b","1: after"); // NULL -> OK
            exists(c,"c","1: after"); // NULL -> OK
            log("");
        }
        exists(a,"a","0: after"); // NULL -> OK
        exists(b,"b","0: after"); // NULL -> OK
        exists(c,"c","0: after"); // NULL -> OK
    }
};

int main(){
    log("");
    {
        ScopeCheck3 sct;
    }
    log("");

    return 0;
}