CODEWITHSUNDEEP
c++
DevMJ
DevMJ

Reputation: 3061

What is best way to copy a C++ structure that contains STL members like vector?

I know that we can not use memcpy() because it can crash the program.

This is the structure that I want to copy. What is the best way to do this?

#pragma pack (push, 1)
typedef struct tagTEST_INFO
{
   char     szCountryCode[100];
   char     szOpFlag[100];
   string   strOrginName;
   vector<RESP_INFO>    vctInfo;
    vector<RESP_HCR_INFO>   vctHcrInfo;

}   TEST_INFO, *P_TEST_INFO;
#pragma pack (pop)

Upvotes: 1

Views: 263

Answers (2)

Bathsheba
Bathsheba

Reputation: 234795

The best thing equipped to write the code to perform your copy is the compiler. But it needs your help.

If RESP_INFO and RESP_HCR_INFO are trivially copyable then the compiler will generate adequate copy constructors and assignment operators automatically.

Also drop the C-style typedef idiom - it's unnecessary in C++. And is that non-portable packing directive really needed? Let the compiler figure out the best way. Moving on, the std::string class would probably be a better type for szCountryCode and szOpFlag.

Upvotes: 1

user6160478
user6160478

Reputation: 119

All of your members have assignment operators defined, meaning the built-in assignment operator will copy just fine. It will do a memberwise copy, which in turns calls the assignment operator of the members. You don't need to define your own copy assignment operator.

Upvotes: 0

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