c++ - How to find out if an item is present in a std::vector?

(C++17 and above):

can use std::search also

This is also useful for searching sequence of elements.

#include 
#include 
#include 

template 
bool search_vector(const Container& vec, const Container& searchvec)

{
    return std::search(vec.begin(), vec.end(), searchvec.begin(), searchvec.end()) != vec.end();
}

int main()
{
     std::vector v = {2,4,6,8};

     //THIS WORKS. SEARCHING ONLY ONE ELEMENT.
     std::vector searchVector1 = {2};

     if(search_vector(v,searchVector1))
         std::cout<<"searchVector1 found"<     else
         std::cout<<"searchVector1 not found"<
     //THIS WORKS, AS THE ELEMENTS ARE SEQUENTIAL.
     std::vector searchVector2 = {6,8};
     if(search_vector(v,searchVector2))
         std::cout<<"searchVector2 found"<     else

         std::cout<<"searchVector2 not found"<
     //THIS WILL NOT WORK, AS THE ELEMENTS ARE NOT SEQUENTIAL.
     std::vector searchVector3 = {8,6};
     if(search_vector(v,searchVector3))
         std::cout<<"searchVector3 found"<     else
         std::cout<<"searchVector3 not found"<}

Also there is flexibility of passing some search algorithms. Refer here.

https://en.cppreference.com/w/cpp/algorithm/search