How to use strip or stripRight on char[len] ? Thanks.

[FrankLike]

Hi,everyone,
How to use strip or stripRight on char[len]?

For example:

string abcs ="aabc    ";
auto abcsaa = abcs.stripRight;
writeln(abcsaa);
writeln("---abcsaa--stripRight ok---- ");


  char[100] abc ="aabc    ";
  auto abcaa = ((abc).dup).stripRight;
  writeln(abcaa);
writeln("----stripRight error----- ");

Where is error? Thanks.