std::valarray::apply

 

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通用的数值运算 Original: Generic numeric operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

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std::valarray

成员函数 Original: Member functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
valarray::valarray valarray::~valarray valarray::operator= valarray::operator[] valarray::swap valarray::size valarray::resize valarray::sum valarray::min valarray::max valarray::shift valarray::cshift valarray::apply	valarray::operator+ valarray::operator- valarray::operator~ valarray::operator! valarray::operator+= valarray::operator-= valarray::operator*= valarray::operator/= valarray::operator%= valarray::operator&= valarray::operator|= valarray::operator^= valarray::operator<<= valarray::operator>>=
非成员函数 Original: Non-member functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
swap （C++11） begin （C++11） end （C++11） abs exp log log10 pow sqrt sin cos tan asin acos atan atan2 sinh cosh tanh	operator* operator/ operator% operator+ operator- operator^ None operator& operator| operator<< operator>> operator&& operator None operator== operator!= operator< operator> operator<= operator>=
Helper类 Original: Helper classes The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
slice_array gslice_array indirect_array	slice gslice mask_array

 

valarray<T> apply( T func(T) ) const;
valarray<T> apply( T func(const T&) ) const;

通过施加到先前的值的元素的功能func购入的大小相同的值返回一个新的valarray.

Original:

Returns a new valarray of the same size with values which are acquired by applying function func to the previous values of the elements.

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参数

func

-

功能适用的值 Original: function to apply to the values The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

返回值

由此产生的valarray与应用功能func，获取的值.

Original:

The resulting valarray with values acquired by applying function func.

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注释

该功能可以实现从std::valarray不同的返回类型。在这种情况下，替换类型具有以下属性：

Original:

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

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• const提供的所有std::valarray成员函数.

  Original:

  All const member functions of std::valarray are provided.

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• std::valarray，std::slice_array，std::gslice_array，std::mask_array和std::indirect_array可以由更换型.

  Original:

  std::valarray, std::slice_array, std::gslice_array, std::mask_array and std::indirect_array can be constructed from the replacement type.

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• 所有的函数接受一个参数的类型const std::valarray&也应接受替换类型.

  Original:

  All functions accepting a arguments of type const std::valarray& should also accept the replacement type.

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• 接受两个参数的类型const std::valarray&应该接受所有的功能const std::valarray&的每个组合和置换型.

  Original:

  All functions accepting two arguments of type const std::valarray& should accept every combination of const std::valarray& and the replacement type.

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为例

第10阶乘计算和打印

Original:

calculates and prints the first 10 factorials

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#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

另请参阅

for_each	某一范围的元素应用一个函数 Original: applies a function to a range of elements The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数模板）