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select2nd<Pair>
DescriptionSelect2nd is a function object that takes a single argument, a pair [1], and returns the pair's second element.ExamplePrint all of a map's values.int main() { map<int, double> M; M[1] = 0.3; M[47] = 0.8; M[33] = 0.1; transform(M.begin(), M.end(), ostream_iterator<double>(cout, " "), select2nd<map<int, double>::value_type>()); // The output is 0.3 0.1 0.8 } DefinitionDefined in the standard header functional, and in the nonstandard backward-compatibility header function.h. This function object is an SGI extension; it is not part of the C++ standard.Template parameters
Model ofAdaptable Unary FunctionType requirementsThere exist some types U and V such that Pair provides the same interface as a pair<U,V>. [1]Public base classesunary_function<Pair, Pair::second_type>Members
New membersAll of select2nd's members are defined in the Adaptable Unary Function requirements. Select2nd does not introduce any new members.Notes[1] Pair is not actually required to be a pair<U,V>, but merely to support the same interface as pair. In almost all cases the template parameter will be a pair, but it is occasionally useful for it to be something else. One example is a struct that has the members first, second, and third. See alsoidentity, select1st, project1st, project2ndCopyright © 1999 Silicon Graphics, Inc. All Rights Reserved. TrademarkInformation
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