clang/test/SemaCXX/bitfield.cpp

   1 // RUN: %clang_cc1 %s -verify
   2
   3 // expected-no-diagnostics
   4
   5 namespace PromotionVersusMutation {
   6   typedef unsigned Unsigned;
   7   typedef signed Signed;
   8
   9   struct T { unsigned n : 2; } t;
  10
  11   typedef __typeof__(t.n) Unsigned; // Bitfield is unsigned
  12   typedef __typeof__(+t.n) Signed;  // ... but promotes to signed.
  13
  14   typedef __typeof__(t.n + 0) Signed; // Arithmetic promotes.
  15
  16   typedef __typeof__(t.n = 0) Unsigned;  // Assignment produces an lvalue...
  17   typedef __typeof__(t.n += 0) Unsigned;
  18   typedef __typeof__(t.n *= 0) Unsigned;
  19   typedef __typeof__(+(t.n = 0)) Signed;  // ... which is a bit-field.
  20   typedef __typeof__(+(t.n += 0)) Signed;
  21   typedef __typeof__(+(t.n *= 0)) Signed;
  22
  23   typedef __typeof__(++t.n) Unsigned; // Increment is equivalent to compound-assignment.
  24   typedef __typeof__(--t.n) Unsigned;
  25   typedef __typeof__(+(++t.n)) Signed;
  26   typedef __typeof__(+(--t.n)) Signed;
  27
  28   typedef __typeof__(t.n++) Unsigned; // Post-increment's result has the type
  29   typedef __typeof__(t.n--) Unsigned; // of the operand...
  30   typedef __typeof__(+(t.n++)) Unsigned; // ... and is not a bit-field (because
  31   typedef __typeof__(+(t.n--)) Unsigned; // it's not a glvalue).
  32 }