Re: member variable of STL string class
George wrote:
Thanks Uli,
1.
George wrote:
So, learned from your answer to my question 1, I think is _Buf is
used to hold small sized content, and _Ptr is used to hold larger
sizes content. Small sized content is on stack and larger sized
content is on heap, correct?
No.
Why? Could you give more information about how you make the
conclusion please?
What makes you think that
std::string* p = new std::string("Short");
could put the content { 'S', 'h', 'o', 'r', 't', '\0' } on the stack? The
lifetime of the string object and its content have to be dynamic, while
stack variables lifetime end when the scope is closed (most likely the end
of the function). Of course, being a string literal, the same string will
also be stored in a read-only segment, but the string must have its own
writable copy of the content.
Short content is inside the string object. The string object can be many
places: stack, heap, global data segment, etc.
Longer string content is on the heap as you said.
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