c++ - std::vector::reserve Invalidation -

If I call std :: vector :: reserve then a certain quantity In memory vector, I will not delete my vector , or any method call (maybe clear ) will free my reserved memory, it will save the memory ?

edit : I will use the container again and again, because of performance reasons I want to avoid memory allocation. For this reason I keep the memory in front, so I want to be sure that nothing is done to lose allocated memory.

Edit: Due to performance, I want to avoid memory allocation, so I use the container bar I will use it again. This is because I reserve the memory so I want to be sure that I do nothing to lose allocated memory.

You only need to avoid two things:

1. , But this is only request for free memory, in fact it is not necessary for vector to do this.

The ability to make only swap with 2 empty vectors will change (see see):

  vector < Int & gt; V; V.reserve (100); Of vector & lt; Int>. () Swap (v); Esrete (v.capacity () == 0);   
 Neither vector nor vector capacity will be reduced by small size.  
 Consider using BTW.