From ba81d275b4ede69d75bf1b98576f040b493106cb Mon Sep 17 00:00:00 2001
From: Soyn <w604408482@163.com>
Date: Sat, 30 Apr 2016 17:24:31 +0800
Subject: [PATCH 1/3] add the exception safety solution for copy-assignment
 operator

---
 ch13/ex13_08.h | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/ch13/ex13_08.h b/ch13/ex13_08.h
index 9192c807..70beb2ed 100644
--- a/ch13/ex13_08.h
+++ b/ch13/ex13_08.h
@@ -7,7 +7,7 @@
 //  Write the assignment operator for the HasPtr class from exercise 13.5 in 13.1.1 (p. 499).
 //  As with the copy constructor, your assignment operator should copy the object to which ps points.
 //
-//  See ex13_05.h 
+//  See ex13_05.h
 
 #ifndef CP5_ex13_08_h
 #define CP5_ex13_08_h
@@ -18,11 +18,18 @@ class HasPtr {
 public:
     HasPtr(const std::string &s = std::string()) : ps(new std::string(s)), i(0) { }
     HasPtr(const HasPtr &hp) : ps(new std::string(*hp.ps)), i(hp.i) { }
-    HasPtr& operator=(const HasPtr &hp) {
-        std::string *new_ps = new std::string(*hp.ps);
-        delete ps;
-        ps = new_ps;
-        i = hp.i;
+    HasPtr& operator=(const HasPtr &rhs_hp) {
+        if(this != &rhs_hp){  // there is no need to assign for
+                              // the same instance.
+
+            HasPtr temp_HasPtr(rhs_hp);
+            std :: string *temp_ps = temp_HasPtr.ps;
+            temp_HasPtr.ps = ps;
+            ps = temp_ps;
+
+            i = temp_HasPtr.i;
+        }  // temp_HasPtr's destructor will be called,
+           // the memory allocated by original instance will be freed.
         return *this;
     }
 private:

From b4a8cf17903099ca39b270bea374f10fe523d9ee Mon Sep 17 00:00:00 2001
From: Soyn <w604408482@163.com>
Date: Tue, 3 May 2016 15:45:58 +0800
Subject: [PATCH 2/3] fix the solution

---
 ch13/ex13_08.h | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/ch13/ex13_08.h b/ch13/ex13_08.h
index 70beb2ed..59cf76c4 100644
--- a/ch13/ex13_08.h
+++ b/ch13/ex13_08.h
@@ -19,17 +19,12 @@ class HasPtr {
     HasPtr(const std::string &s = std::string()) : ps(new std::string(s)), i(0) { }
     HasPtr(const HasPtr &hp) : ps(new std::string(*hp.ps)), i(hp.i) { }
     HasPtr& operator=(const HasPtr &rhs_hp) {
-        if(this != &rhs_hp){  // there is no need to assign for
-                              // the same instance.
-
-            HasPtr temp_HasPtr(rhs_hp);
-            std :: string *temp_ps = temp_HasPtr.ps;
-            temp_HasPtr.ps = ps;
+        if(this != &rhs_hp){
+            std :: string *temp_ps = new std :: string(*rhs_hp);
+            delete ps;
             ps = temp_ps;
-
-            i = temp_HasPtr.i;
-        }  // temp_HasPtr's destructor will be called,
-           // the memory allocated by original instance will be freed.
+            i = rhs_hp.i;
+        }
         return *this;
     }
 private:

From 3f6de3125149891ac66268138ce4f025160feddd Mon Sep 17 00:00:00 2001
From: Soyn <w604408482@163.com>
Date: Tue, 3 May 2016 16:12:52 +0800
Subject: [PATCH 3/3] fix

---
 ch13/ex13_08.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ch13/ex13_08.h b/ch13/ex13_08.h
index 59cf76c4..1f01fdad 100644
--- a/ch13/ex13_08.h
+++ b/ch13/ex13_08.h
@@ -20,7 +20,7 @@ class HasPtr {
     HasPtr(const HasPtr &hp) : ps(new std::string(*hp.ps)), i(hp.i) { }
     HasPtr& operator=(const HasPtr &rhs_hp) {
         if(this != &rhs_hp){
-            std :: string *temp_ps = new std :: string(*rhs_hp);
+            std::string *temp_ps = new std::string(*rhs_hp.ps);
             delete ps;
             ps = temp_ps;
             i = rhs_hp.i;