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POc++ how to solve my memory leak?
primarykey
Id
11352774
data
AcceptedAnswerId
11354436
AnswerCount
3
ClosedDate
CommentCount
11
CommunityOwnedDate
CreationDate
2012-07-05T21:22:45.443
FavoriteCount
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LastActivityDate
2012-07-09T20:46:17.843
LastEditDate
2017-05-23T12:12:28.187
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Score
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ViewCount
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LastEditorDisplayName
text
Body
Consider the following implemntation of a Binary class representation of an integer: <pre><code>class Binary { private: int *digits; int first1; public: Binary() { digits = new int[128]; digits[0]=0; first1=0; } ~Binary() { cout<<"deleting"<<endl; delete [] digits; } Binary(const Binary& b){ digits = new int[128]; memcpy(digits,b.digits,128*sizeof(int)); first1=b.first1; } explicit Binary(double x){ int n=(int)x,i; digits = new int[128]; for (i=0; n ; i++,n>>=1) digits[i]=(n & 1)? 1:0; first1=i-1; } Binary& operator =(const Binary& b){ if (this==&b) return *this; memcpy(digits,b.digits,128*sizeof(int)); first1=b.first1; return *this; } Binary(int n) { int i; digits = new int[128]; for (i=0; n ; i++,n>>=1) digits[i]=(n & 1)? 1:0; first1=i-1; } void print() { for (int i=first1; i>=0 ; i--) cout<<digits[i]; cout<<endl; } operator int() { int x = 1,sum=0; for (int i=0; i<=first1 ; i++,x<<=1) sum+=digits[i]*x; return sum; } Binary& operator +(Binary& a) { int overflow = 0; Binary* b1=new Binary(); int max = a.first1>this->first1? a.first1 : this->first1,bit; for (int i=0; i<=max ; i++) { bit=a.digits[i]+this->digits[i]+overflow; overflow=0; if (bit>1) overflow=1; b1->digits[i]=bit%2; } return *b1; } }; </code></pre> and the main using it: <pre><code>int main() { Binary b(91); int x=9; Binary *b2=new Binary(); *b2=b+x; x=*b2; b2->print(); cout<<" = "<<x; cin>>x; } </code></pre> lets talk about the line: <pre><code>*b2=b+x; </code></pre> first the compiler implicitly allocates a new binary instance for int x, then using it as a paramater for the addition, then creates a new binary instance for the addition result and copies it bit by bit to *b2. The problem is, that if you run this code, it only prints deleting ONCE, while there were 2 objects created for the execution of the command. apparently there's a leak comes from the addition code, in which i explicitly created a new object to return the result. Q1: am i correct? Q2: what can i do to overcome this? EDIT: The answer and more about the topic of operator overloading can be found <a href="https://stackoverflow.com/questions/4421706/operator-overloading">here</a>
Tags
<c++><memory><copy-constructor>
Title
c++ how to solve my memory leak?
singulars
PostAcceptedAnswerId
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
PostParentId
1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
UserLastEditorUserId
1. USCommunity
UserOwnerUserId
1. USOfek Ron
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PostLinksPostIdRelatedPostId
1. PL
 singulars
 LinkTypeLinkTypeId
 LTLinked
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. PO
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 PostTypePostTypeId
 PTAnswer
2. PO
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 PostTypePostTypeId
 PTAnswer
3. PO
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 PostTypePostTypeId
 PTAnswer
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1. VO
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 PostPostId
 POc++ how to solve my memory leak?
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 VTUpMod
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