Was there ever a proposal to have Vecs auto shrink (and if so, why was it rejected). Auto shrink here defined as:
if len <= capacity / 4, shrink capacity down to capacity / 2
(basically the inverse of double when out of space)
Was there ever a proposal to have Vecs auto shrink (and if so, why was it rejected). Auto shrink here defined as:
if len <= capacity / 4, shrink capacity down to capacity / 2
(basically the inverse of double when out of space)
It's the common behavior across languages including C++ std::vector
and Java ArrayList
, so proposals and conversations may scattered over decades. Searching those terms instead would yields better result like this as they existed longer and have a lot more accumulated users.
If interpreted strictly, it would make Vec::with_capacity
a synonym for Vec::new
.
Less cheekily, it's a horrible fit for things like buffers where you set the length to 0 often. Especially if you know the size you do need in advance.
You could make a new type that does it.
Doing a reallocation every time you clear a Vec would be less than great for performance and also be mostly redundant since Vec::shrink_to()
and Vec::shrink_to_fit()
already exist. It would also go against rust's general philosophy of not quietly performing magic behind your back.
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