Delete no_non_exhaustive configuration

build.rs

@@ -11,20 +11,13 @@ fn main() {
     };
 
     if compiler >= 80 {
-        println!("cargo:rustc-check-cfg=cfg(no_non_exhaustive)");
         println!("cargo:rustc-check-cfg=cfg(no_nonzero_bitscan)");
         println!("cargo:rustc-check-cfg=cfg(no_str_strip_prefix)");
         println!("cargo:rustc-check-cfg=cfg(no_track_caller)");
         println!("cargo:rustc-check-cfg=cfg(no_unsafe_op_in_unsafe_fn_lint)");
         println!("cargo:rustc-check-cfg=cfg(test_node_semver)");
     }
 
-    if compiler < 40 {
-        // #[non_exhaustive].
-        // https://blog.rust-lang.org/2019/12/19/Rust-1.40.0.html#non_exhaustive-structs-enums-and-variants
-        println!("cargo:rustc-cfg=no_non_exhaustive");
-    }
-
     if compiler < 45 {
         // String::strip_prefix.
         // https://doc.rust-lang.org/std/primitive.str.html#method.strip_prefix

src/display.rs

@@ -56,8 +56,6 @@ impl Display for Comparator {
             Op::Tilde => "~",
             Op::Caret => "^",
             Op::Wildcard => "",
-            #[cfg(no_non_exhaustive)]
-            Op::__NonExhaustive => unreachable!(),
         };
         formatter.write_str(op)?;
         write!(formatter, "{}", self.major)?;

src/eval.rs

@@ -36,8 +36,6 @@ fn matches_impl(cmp: &Comparator, ver: &Version) -> bool {
         Op::LessEq => matches_exact(cmp, ver) || matches_less(cmp, ver),
         Op::Tilde => matches_tilde(cmp, ver),
         Op::Caret => matches_caret(cmp, ver),
-        #[cfg(no_non_exhaustive)]
-        Op::__NonExhaustive => unreachable!(),
     }
 }
 

src/lib.rs

@@ -250,7 +250,7 @@ pub struct Comparator {
 /// -  **`I.J.*`** — equivalent to `=I.J`
 /// -  **`I.*`** or **`I.*.*`** — equivalent to `=I`
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
-#[cfg_attr(not(no_non_exhaustive), non_exhaustive)]
+#[non_exhaustive]
 pub enum Op {
     Exact,
     Greater,
@@ -260,10 +260,6 @@ pub enum Op {
     Tilde,
     Caret,
     Wildcard,
-
-    #[cfg(no_non_exhaustive)] // rustc <1.40
-    #[doc(hidden)]
-    __NonExhaustive,
 }
 
 /// Optional pre-release identifier on a version string. This comes after `-` in