string memory pre-allocation

[Jarek]

Hi all!

As I understand string class, whenever string is expanded (i.e. by +=
), the memory is reallocated with new bigger size.
Is it makes sense ( from perforamance point of view ) to pre-allocate
some memory for string, i.e.:

string temp(100,' ');

temp.clear();


temp += "a";
temp += "b";
...


Jarek

 

[Tim Love]

Hi all!

As I understand string class, whenever string is expanded (i.e. by +=
), the memory is reallocated with new bigger size.

Not really. Read about size(), capacity(), and reserve() member functions.