[Bug libstdc++/52938] std::string::reserve request is not maintained if object is used in other object copy ctore

[abdul.tohmaz at emc dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52938

--- Comment #2 from Abdul Tohmaz <abdul.tohmaz at emc dot com> 2012-04-11 20:32:26 UTC ---
(In reply to comment #1)
> Why do you think this is a bug?  I don't see why x="aaa"; would not change the
> reserve.  
> 
> The main reason why it changes the reserve is that the backing part is shared
> between x and y.

I have called:
x.reserve(20); 
which I expect that 20 bytes (at least) to be reserved to this string.  So I
would expect no memory reallocation as long as my string can fit in my reserved
request.

Then I called x="aaa"; 
and then
x += "bbb";

Why do I see memory is being reallocated even though the string x content can
fit within what I requested in my reserve call?