character_concat_string_string Function

   elemental function character_concat_string_string(lhs, rhs) result(concat)
   !< Concatenation with character (inverted).
   !<
   !<```fortran
   !< type(string)                  :: astring
   !< type(string)                  :: yetanotherstring
   !< character(len=:), allocatable :: acharacter
   !< logical                       :: test_passed(1)
   !< astring = 'Hello '
   !< acharacter = 'World!'
   !< yetanotherstring = acharacter.cat.astring
   !< test_passed(1) = yetanotherstring%chars()=='World!Hello '
   !< print '(L1)', all(test_passed)
   !<```
   !=> T <<<
   character(kind=CK, len=*), intent(in)  :: lhs    !< Left hand side.
   class(string),             intent(in)  :: rhs    !< Right hand side.
   type(string)                           :: concat !< Concatenated string.

   if (allocated(rhs%raw)) then
     concat%raw = lhs//rhs%raw
   else
     concat%raw = lhs
   endif
   endfunction character_concat_string_string