vec not free memory.

[zhangxize]

vec not free momeny.

main.zip

[zhangxize]

Before the 6th attempt, the memory increased slightly and then stopped at 277M

[thynson]

It is working as intended and depends on the implementation of the memory allocator.

When a Vec is dropped, the corresponding memory is returned to the allocator, while the allocator may keep it for next allocation, instead of returning it to the OS directly.

[saethlin]

This is a common observation about heap allocators. It's rather vexing, but not releasing memory to the OS is an important optimization.