Does reserving capacity incur two allocations or just one?

Posted by FredOverflow on Stack Overflow See other posts from Stack Overflow or by FredOverflow
Published on 2010-05-01T00:27:08Z Indexed on 2010/05/01 0:37 UTC
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c++

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stl

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vector

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memory-allocation

std::vector<T> vec;   // line #1
vec.reserve(100);     // line #2

I am wondering if line #1 triggers a small allocation (say, memory for 10 Ts), or if the first allocation happens on line #2. Does the standard say anything about that?

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