Implement a module attribute 'optional' to allow missing headers.

This deals with the fact that our modulemaps include headers which can vary across library versions and that attribute is a way to express this.
2023-03-27 19:43:33 +00:00 · 2023-03-27 19:43:33 +00:00 · f7571c07f5
commit f7571c07f5
parent d09d5a71b7
1 changed files with 2 additions and 2 deletions
--- a/include/cling/std.modulemap
+++ b/include/cling/std.modulemap
@ -429,8 +429,8 @@ module "std" [system] {
    export *
    header "bits/basic_ios.h"
  }
-  module "bits/chrono.h" {
-    requires cplusplus20
+  module "bits/chrono.h" [optional] {
+    requires cplusplus17
    export *
    header "bits/chrono.h"
  }