Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
366 views
in Technique[技术] by (71.8m points)

c++ - Does a pointer returned by std::string.c_str() or std::string.data() have to be freed?

As far as i know, std::string creates a ident array-copy of its content when you call the c_str()/data() methods (with/out terminating NUL-char, does not matter here). Anyway, does the object also take care of freeing this array or do I have to?

In short:

std::string hello("content");

const char* Ptr = hello.c_str();

// use it....

delete[] Ptr;   //// really ???

I just want to be on the safe side when it comes to memory allocation.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

No you don't need to deallocate the ptr pointer.

ptr points to a non modifyable string located somewhere to an internal location(actually this is implementation detail of the compilers).


Reference:

C++ documentation:

const char* c_str ( ) const;

Get C string equivalent

Generates a null-terminated sequence of characters (c-string) with the same content as the string object and returns it as a pointer to an array of characters.

A terminating null character is automatically appended.

The returned array points to an internal location with the required storage space for this sequence of characters plus its terminating null-character, but the values in this array should not be modified in the program and are only guaranteed to remain unchanged until the next call to a non-constant member function of the string object.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...