1 #[allow(unused_assignments, unused_mut, unused_variables)] 2 pub const STD: &str = { 3 let mut flag = "c++11"; 4 5 #[cfg(feature = "c++14")] 6 (flag = "c++14"); 7 8 #[cfg(feature = "c++17")] 9 (flag = "c++17"); 10 11 #[cfg(feature = "c++20")] 12 (flag = "c++20"); 13 14 flag 15 }; 16