[pan: 1/6] Fix compilation error under clang

[Dominique Dumont <ddumont src gnome org>]

commit 793fdecceb37d7a453d9bd8a7e8795fa28413f7f
Author: Thomas Tanner <thosrtanner googlemail com>
Date:   Sat Jul 16 17:15:05 2022 +0100

    Fix compilation error under clang

 pan/general/string-view.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/pan/general/string-view.h b/pan/general/string-view.h
index e5f8bf7..bff967d 100644
--- a/pan/general/string-view.h
+++ b/pan/general/string-view.h
@@ -86,7 +86,7 @@ namespace pan
          StringView (const char * s, size_t l) { assign(s,l); }
          StringView (const char * s, const char * e) { assign(s,e-s); }
          StringView (const StringView& p): str(p.str), len(p.len) {}
-         constexpr StringView& operator=(StringView const &) = default;
+         StringView& operator=(StringView const &) = default;
          ~StringView () { str = (char*)0xDEADBEEF; len = (size_t)~0; }
 
       public: