Hint Directives

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Using Hint Directives

Whenever an identifier marked with a hint directive is later encountered by the compiler, then a warning will be displayed, corresponding to the specified hint.

  • deprecated
    • The use of this identifier is deprecated, use an alternative instead. The deprecated keyword can be followed by a string constant with a message. The compiler will show this message whenever the identifier is encountered.
  • experimental
    • The use of this identifier is experimental: this can be used to flag new features that should be used with caution.
  • platform
    • This is a platform-dependent identifier: it may not be defined on all platforms.
  • unimplemented
    • This should be used on functions and procedures only. It should be used to signal that a particular feature has not yet been implemented.

The following are examples:

Const  
  AConst = 12 deprecated;  
 
var  
  p : integer platform;  
 
Function Something : Integer; experimental;  
 
begin  
  Something:=P+AConst;  
end;  
 
begin  
  Something;  
end.

This would result in the following output:

testhd.pp(11,15) Warning: Symbol "p" is not portable  
testhd.pp(11,22) Warning: Symbol "AConst" is deprecated  
testhd.pp(15,3) Warning: Symbol "Something" is experimental

Hint directives can follow all kinds of identifiers: units, constants, types, variables, functions, procedures and methods.