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std::valarray::apply

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< cpp‎ | numeric‎ | valarray
Revision as of 14:33, 2 November 2012 by P12bot (Talk | contribs)

 
 
 
 

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valarray<T> apply( T func(T) ) const;
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valarray<T> apply( T func(const T&) ) const;
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Returns a new valarray of the same size with values which are acquired by applying function func to the previous values of the elements.

Contents

Parameters

func - function to apply to the values

Return value

The resulting valarray with values acquired by applying function func.

Notes

The function can be implemented with the return type different from std::valarray. In this case, the replacement type has the following properties:

  • All const member functions of std::valarray are provided.
  • std::valarray, std::slice_array, std::gslice_array, std::mask_array and std::indirect_array can be constructed from the replacement type.
  • All functions accepting a arguments of type const std::valarray& should also accept the replacement type.
  • All functions accepting two arguments of type const std::valarray& should accept every combination of const std::valarray& and the replacement type.
  • The return type does not add more than two levels of template nesting over the most deeply-nested argument type.

Example

calculates and prints the first 10 factorials

#include <iostream>
#include <valarray>
#include <cmath>
 
int main()
{
    std::valarray<int> v = {1,2,3,4,5,6,7,8,9,10};
    v = v.apply([](int n)->int {
                    return std::round(std::tgamma(n+1));
                });
    for(auto n : v) {
        std::cout << n << ' ';
    }
    std::cout << '\n';
}

Output:

1 2 6 24 120 720 5040 40320 362880 3628800

See also

Template:cpp/algorithm/dcl list for each