gcc/testsuite/gdc.test/compilable/test22133.d

   1 // https://issues.dlang.org/show_bug.cgi?id=22133
   2
   3 struct Slice
   4 {
   5     bool empty() const;
   6     int front() const;
   7     void popFront()() // note: requires a mutable Slice
   8     {}
   9 }
  10
  11 enum isInputRange1(R) = is(typeof((R r) => r.popFront));
  12 enum isInputRange2(R) = __traits(compiles, (R r) => r.popFront);
  13 static assert(isInputRange1!(      Slice) == true);
  14 static assert(isInputRange1!(const Slice) == false);
  15 static assert(isInputRange2!(      Slice) == true);
  16 static assert(isInputRange2!(const Slice) == false);