clang/test/SemaCXX/convert-to-bool.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify %s
   2 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++98 %s
   3 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
   4
   5 struct ConvToBool {
   6   operator bool() const;
   7 };
   8
   9 struct ConvToInt {
  10   operator int();
  11 };
  12
  13 struct ExplicitConvToBool {
  14   explicit operator bool(); // expected-note {{explicit}}
  15 #if __cplusplus <= 199711L // C++03 or earlier modes
  16   // expected-warning@-2{{explicit conversion functions are a C++11 extension}}
  17 #endif
  18 };
  19
  20 void test_conv_to_bool(ConvToBool ctb, ConvToInt cti, ExplicitConvToBool ecb) {
  21   if (ctb) { }
  22   if (cti) { }
  23   if (ecb) { }
  24   for (; ctb; ) { }
  25   for (; cti; ) { }
  26   for (; ecb; ) { }
  27   while (ctb) { };
  28   while (cti) { }
  29   while (ecb) { }
  30   do { } while (ctb);
  31   do { } while (cti);
  32   do { } while (ecb);
  33
  34   if (!ctb) { }
  35   if (!cti) { }
  36   if (!ecb) { }
  37
  38   bool b1 = !ecb;
  39   if (ctb && ecb) { }
  40   bool b2 = ctb && ecb;
  41   if (ctb || ecb) { }
  42   bool b3 = ctb || ecb;
  43 }
  44
  45 void accepts_bool(bool) { } // expected-note{{candidate function}}
  46
  47 struct ExplicitConvToRef {
  48   explicit operator int&(); // expected-note {{explicit}}
  49 #if (__cplusplus <= 199711L) // C++03 or earlier modes
  50   // expected-warning@-2{{explicit conversion functions are a C++11 extension}}
  51 #endif
  52 };
  53
  54 void test_explicit_bool(ExplicitConvToBool ecb) {
  55   bool b1(ecb); // okay
  56   bool b2 = ecb; // expected-error{{no viable conversion from 'ExplicitConvToBool' to 'bool'}}
  57   accepts_bool(ecb); // expected-error{{no matching function for call to}}
  58 }
  59
  60 void test_explicit_conv_to_ref(ExplicitConvToRef ecr) {
  61   int& i1 = ecr; // expected-error{{no viable conversion from 'ExplicitConvToRef' to 'int'}}
  62   int& i2(ecr); // okay
  63 }
  64
  65 struct A { };
  66 struct B { };
  67 struct C {
  68   explicit operator A&();  // expected-note {{explicit}}
  69 #if __cplusplus <= 199711L // C++03 or earlier modes
  70 // expected-warning@-2{{explicit conversion functions are a C++11 extension}}
  71 #endif
  72   operator B&(); // expected-note{{candidate}}
  73 };
  74
  75 void test_copy_init_conversions(C c) {
  76   A &a = c; // expected-error{{no viable conversion from 'C' to 'A'}}
  77   B &b = c; // okay
  78 }