You do not need to reserve memory for the container when using std::back_inserter
. However, if you know beforehand about the number of elements you are going to insert and want to prevent repeated allocations you may reserve memory.
Should I reserve memory when using std::back_inserter
题
Do I need to reserve memory when using a back:inserter?
d.reserve(s.size())
std::copy (s.begin(),s.end(),back_inserter(d));
解决方案
其他提示
You don't have to. However, if this code snippet is run very frequently, you may consider reserving memory to improve performance.
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