+{ # related to [perl #27940]
+ ok("\0-A" =~ /\c@-A/, '@- should not be interpolated in a pattern');
+ ok("\0\0A" =~ /\c@+A/, '@+ should not be interpolated in a pattern');
+ ok("X\@-A" =~ /X@-A/, '@- should not be interpolated in a pattern');
+ ok("X\@\@A" =~ /X@+A/, '@+ should not be interpolated in a pattern');
+
+ ok("X\0A" =~ /X\c@?A/, '\c@?');
+ ok("X\0A" =~ /X\c@*A/, '\c@*');
+ ok("X\0A" =~ /X\c@(A)/, '\c@(');
+ ok("X\0A" =~ /X(\c@)A/, '\c@)');
+ ok("X\0A" =~ /X\c@|ZA/, '\c@|');
+
+ ok("X\@A" =~ /X@?A/, '@?');
+ ok("X\@A" =~ /X@*A/, '@*');
+ ok("X\@A" =~ /X@(A)/, '@(');
+ ok("X\@A" =~ /X(@)A/, '@)');
+ ok("X\@A" =~ /X@|ZA/, '@|');
+
+ local $" = ','; # non-whitespace and non-RE-specific
+ ok('abc' =~ /(.)(.)(.)/, 'the last successful match is bogus');
+ ok("A@+B" =~ /A@{+}B/, 'interpolation of @+ in /@{+}/');
+ ok("A@-B" =~ /A@{-}B/, 'interpolation of @- in /@{-}/');
+ ok("A@+B" =~ /A@{+}B/x, 'interpolation of @+ in /@{+}/x');
+ ok("A@-B" =~ /A@{-}B/x, 'interpolation of @- in /@{-}/x');
+}
+