1.5 Hint directives

Most identifiers (constants, variables, functions or methods, properties) can have a hint directive appended to their definition:

_________________________________________________________________________________________________________
Hint directives

--hint-directive--|-------------------------------------------------
              -Deprecated -|---------------|
              |            -string- constant-- |
              |-------Experimental---------|
              ----------Platform  ----------|
                     Unimplemented
___________________________________________________________________

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.