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A handle service must meet the requirements for an I/O object service with support for movability, as well as the additional requirements listed below.
        In the table below, X denotes
        a handle service class, a
        and ao denote values of type
        X, b
        and c denote values of type
        X::implementation_type, n
        denotes a value of type X::native_handle_type,
        ec denotes a value of type
        error_code, and u and v
        denote identifiers.
      
Table 14. HandleService requirements
| expression | return type | 
                  assertion/note | 
|---|---|---|
| 
                   | 
                  The implementation-defined native representation of a handle. Must
                  satisfy the requirements of  | |
| 
                   | 
                  From IoObjectService
                  requirements. | |
| 
                   | 
                  From IoObjectService
                  requirements. Implicitly cancels asynchronous operations, as if
                  by calling  | |
| 
 a.move_construct(b, c); 
 | 
                  From IoObjectService
                  requirements. The underlying native representation is moved from
                   | |
| 
 a.move_assign(b, ao, c); 
 | 
                  From IoObjectService
                  requirements. Implicitly cancels asynchronous operations associated
                  with  | |
| 
 a.assign(b, n, ec); 
 | 
                   | 
                  pre:  | 
| 
 a.is_open(b); 
 | 
                   | |
| 
 const X& u = a; const X::implementation_type& v = b; u.is_open(v); 
 | 
                   | |
| 
 a.close(b, ec); 
 | 
                   | 
                  If  | 
| 
 a.native_handle(b); 
 | 
                   | |
| 
 a.cancel(b, ec); 
 | 
                   | 
                  pre:  |