Thread: why not working?

Code:

#include<vector>
#include<cmath>
#include<iostream>






int main()
{
    std::vector<int> ints{ 0, 1, 2, 3, 4, 5 };
    auto even = [](int i) { return i % 2 == 0;  };
    auto square = [](int i) { return i * i;  };


    for (int i : ints | std::views::filter(even) |
        std::views::transform(square)) {
        std::cout << i << ' ';
    }
}

It says two errors, but I did the example straight from the book...

What exactly are the errors?

Originally Posted by jimblumberg

What exactly are the errors?

Says:

Code:

main.cpp:17:30: error: ‘std::views’ has not been declared   17 |     for (int i : ints | std::views::filter(even) |
      |                              ^~~~~
main.cpp:18:14: error: ‘std::views’ has not been declared
   18 |         std::views::transform(square)) {       |              ^~~~~

You also need to include <ranges>, then it works with my VS2019

I was using C++ 20....

Originally Posted by laserlight

You need to compile as C++20, or if your compiler does not support C++20, then you need to upgrade compiler.

Can you show your code? Because I used

Code:

#include<ranges>

and it did not work...

Originally Posted by thmm

You also need to include <ranges>, then it works with my VS2019

It's the same code you posted + the include.
You also need to set the C++ Language Standard

Wow, many thanks. I was using c++ 14, now no longer am. Thank you.

Originally Posted by thmm

It's the same code you posted + the include.
You also need to set the C++ Language Standard