[ edit ] Syntax

[ edit ] Explanation

Indicates that the use of the name or entity declared with this attribute is allowed, but discouraged for some reason. Compilers typically issue warnings on such uses. The string-literal , if specified, is usually included in the warnings.

This attribute is allowed in declarations of the following names or entities:

• struct / union : struct [ [ deprecated ] ] S ; ,
• typedef-name : [ [ deprecated ] ] typedef S * PS ; ,
• objects: [ [ deprecated ] ] int x ; ,
• struct/union member: union U { [ [ deprecated ] ] int n ; } ; ,
• function : [ [ deprecated ] ] void f ( void ) ; ,
• enumeration : enum [ [ deprecated ] ] E { } ; ,
• enumerator: enum { A [ [ deprecated ] ] , B [ [ deprecated ] ] = 42 } ; .

  A name declared non-deprecated may be redeclared deprecated. A name declared deprecated cannot be un-deprecated by redeclaring it without this attribute.

  [ edit ] Example

  Run this code

  #include <stdio.h>
  [[deprecated]]
  void TriassicPeriod(void)
      puts("Triassic Period: [251.9 - 208.5] million years ago.");
  [[deprecated("Use NeogenePeriod() instead.")]]
  void JurassicPeriod(void)
      puts("Jurassic Period: [201.3 - 152.1] million years ago.");
  [[deprecated("Use calcSomethingDifferently(int).")]]
  int calcSomething(int x)
      return x * 2;
  int main(void)
      TriassicPeriod();
      JurassicPeriod();
  Possible output:
  Triassic Period: [251.9 - 208.5] million years ago.
  Jurassic Period: [201.3 - 152.1] million years ago.
  prog.c:23:5: warning: 'TriassicPeriod' is deprecated [-Wdeprecated-declarations]
      TriassicPeriod();
  prog.c:3:3: note: 'TriassicPeriod' has been explicitly marked deprecated here
  [[deprecated]]
  prog.c:24:5: warning: 'JurassicPeriod' is deprecated: Use NeogenePeriod() instead. [-Wdeprecated-declarations]
      JurassicPeriod();
  prog.c:9:3: note: 'JurassicPeriod' has been explicitly marked deprecated here
  [[deprecated("Use NeogenePeriod() instead.")]]
  2 warnings generated.
   
  [edit] See also
  

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