These members of below headers(there may be more) don't need std namespace but works with std:: also
<algorithm>
find() vs std::find(), for_each() vs std::for_each()
<numeric>
accumulate() vs std::accumulate()
Please consider below small program, its here too: https://wandbox.org/permlink/1YxUNYdrFhCZc6qu
//using namespace std; is not present in this program
//we must write std::cout can't just write cout
//but std::find and find both works same is true about for_each
#include <iostream>
#include <vector>
#include <algorithm>
void printer(int e) { std::cout << e << " "; }
int main()
{
std::vector<int> v = {1, 2, 4, 7};
std::vector<int>::iterator it;
//find
it = find(v.begin(), v.end(), 4);
std::cout <<"1] Found: " << *it << '\n';
//std::find
it = std::find(v.begin(), v.end(), 4);
std::cout <<"2] Found: " << *it << '\n';
std::cout << "Printing all elements:\n";
//for_each
std::cout << "1] ";
for_each(v.begin(), v.end(), printer);
//std::for_each
std::cout << "\n2] ";
std::for_each(v.begin(), v.end(), printer);
return 0;
}
Why is it so ? I have tried both g++ and clang, same output.
