c++ - What is more efficient: vector.clear() or if(vector.empty()) clear();? -


as subject states.. version more efficient , why?

std::vector a; ..  a.clear();

or

std::vector a; .. if(!a.empty())   a.clear();

an empty vector valid vector. operation 

a.clear();

is valid on empty vector.

test emptiness before clear unnecessary , time consuming, first 1 more efficient.


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