std::valarray<T>::operator=

valarray<T>& operator=( const valarray<T>& other );

valarray<T>& operator=( valarray<T>&& other ) noexcept;

valarray<T>& operator=( const T& val );

valarray<T>& operator=( const std::slice_array<T>& other );

valarray<T>& operator=( const std::gslice_array<T>& other );

valarray<T>& operator=( const std::mask_array<T>& other );

valarray<T>& operator=( const std::indirect_array<T>& other );

valarray<T>& operator=( std::initializer_list<T> il );

#include <iomanip>
#include <iostream>
#include <valarray>
 
void print(const char* rem, const std::valarray<int>& v)
{
    std::cout << std::left << std::setw(36) << rem << std::right;
    for (int n : v)
        std::cout << std::setw(3) << n;
    std::cout << '\n';
}
 
int main()
{
    std::valarray<int> v1(3);
    v1 = -1; // (3) from a scalar 
    print("assigned from scalar: ", v1);
 
    v1 = {1, 2, 3, 4, 5, 6}; // (8): from initializer list of different size
    print("assigned from initializer_list:", v1);
 
    std::valarray<int> v2(3);
    v2 = v1[std::slice(0, 3, 2)]; // (4): from slice array
    print("every 2nd element starting at pos 0:", v2);
 
    v2 = v1[v1 % 2 == 0]; // (6): from mask array
    print("values that are even:", v2);
 
    std::valarray<std::size_t> idx = {0, 1, 2, 4}; // index array
    v2.resize(4); // sizes must match when assigning from gen subscript
    v2 = v1[idx]; // (7): from indirect array
    print("values at positions 0, 1, 2, 4:", v2);
}