llvm-project/clang/test/SemaCXX/enable_if.cpp

576 lines
25 KiB
C++

// RUN: %clang_cc1 -std=c++11 -verify %s
// RUN: %clang_cc1 -std=c++2a -verify %s
typedef int (*fp)(int);
int surrogate(int);
struct Incomplete; // expected-note{{forward declaration of 'Incomplete'}} \
// expected-note {{forward declaration of 'Incomplete'}}
struct X {
X() = default; // expected-note{{candidate constructor not viable: requires 0 arguments, but 1 was provided}}
X(const X&) = default; // expected-note{{candidate constructor not viable: no known conversion from 'bool' to 'const X' for 1st argument}}
X(bool b) __attribute__((enable_if(b, "chosen when 'b' is true"))); // expected-note{{candidate disabled: chosen when 'b' is true}}
void f(int n) __attribute__((enable_if(n == 0, "chosen when 'n' is zero")));
void f(int n) __attribute__((enable_if(n == 1, "chosen when 'n' is one"))); // expected-note{{member declaration nearly matches}} expected-note 2{{candidate disabled: chosen when 'n' is one}}
void g(int n) __attribute__((enable_if(n == 0, "chosen when 'n' is zero"))); // expected-note{{candidate disabled: chosen when 'n' is zero}}
void h(int n, int m = 0) __attribute__((enable_if(m == 0, "chosen when 'm' is zero"))); // expected-note{{candidate disabled: chosen when 'm' is zero}}
static void s(int n) __attribute__((enable_if(n == 0, "chosen when 'n' is zero"))); // expected-note2{{candidate disabled: chosen when 'n' is zero}}
void conflict(int n) __attribute__((enable_if(n+n == 10, "chosen when 'n' is five"))); // expected-note{{candidate function}}
void conflict(int n) __attribute__((enable_if(n*2 == 10, "chosen when 'n' is five"))); // expected-note{{candidate function}}
void hidden_by_argument_conversion(Incomplete n, int m = 0) __attribute__((enable_if(m == 10, "chosen when 'm' is ten")));
Incomplete hidden_by_incomplete_return_value(int n = 0) __attribute__((enable_if(n == 10, "chosen when 'n' is ten"))); // expected-note{{'hidden_by_incomplete_return_value' declared here}}
operator long() __attribute__((enable_if(true, "chosen on your platform")));
operator int() __attribute__((enable_if(false, "chosen on other platform")));
operator fp() __attribute__((enable_if(false, "never enabled"))) { return surrogate; } // expected-note{{conversion candidate of type 'int (*)(int)'}} // FIXME: the message is not displayed
};
void X::f(int n) __attribute__((enable_if(n == 0, "chosen when 'n' is zero"))) // expected-note{{member declaration nearly matches}} expected-note 2{{candidate disabled: chosen when 'n' is zero}}
{
}
void X::f(int n) __attribute__((enable_if(n == 2, "chosen when 'n' is two"))) // expected-error{{out-of-line definition of 'f' does not match any declaration in 'X'}}
{
}
X x1(true);
X x2(false); // expected-error{{no matching constructor for initialization of 'X'}}
__attribute__((deprecated)) constexpr int old() { return 0; } // expected-note2{{'old' has been explicitly marked deprecated here}}
void deprec1(int i) __attribute__((enable_if(old() == 0, "chosen when old() is zero"))); // expected-warning{{'old' is deprecated}}
void deprec2(int i) __attribute__((enable_if(old() == 0, "chosen when old() is zero"))); // expected-warning{{'old' is deprecated}}
void overloaded(int);
void overloaded(long);
struct Int {
constexpr Int(int i) : i(i) { }
constexpr operator int() const { return i; }
int i;
};
void default_argument(int n, int m = 0) __attribute__((enable_if(m == 0, "chosen when 'm' is zero"))); // expected-note{{candidate disabled: chosen when 'm' is zero}}
void default_argument_promotion(int n, int m = Int(0)) __attribute__((enable_if(m == 0, "chosen when 'm' is zero"))); // expected-note{{candidate disabled: chosen when 'm' is zero}}
struct Nothing { };
template<typename T> void typedep(T t) __attribute__((enable_if(t, ""))); // expected-note{{candidate disabled:}} expected-error{{value of type 'Nothing' is not contextually convertible to 'bool'}}
template<int N> void valuedep() __attribute__((enable_if(N == 1, "")));
// FIXME: we skip potential constant expression evaluation on value dependent
// enable-if expressions
int not_constexpr();
template<int N> void valuedep() __attribute__((enable_if(N == not_constexpr(), "")));
template <typename T> void instantiationdep() __attribute__((enable_if(sizeof(sizeof(T)) != 0, "")));
void test() {
X x;
x.f(0);
x.f(1);
x.f(2); // expected-error{{no matching member function for call to 'f'}}
x.f(3); // expected-error{{no matching member function for call to 'f'}}
x.g(0);
x.g(1); // expected-error{{no matching member function for call to 'g'}}
x.h(0);
x.h(1, 2); // expected-error{{no matching member function for call to 'h'}}
x.s(0);
x.s(1); // expected-error{{no matching member function for call to 's'}}
X::s(0);
X::s(1); // expected-error{{no matching member function for call to 's'}}
x.conflict(5); // expected-error{{call to member function 'conflict' is ambiguous}}
x.hidden_by_argument_conversion(10); // expected-error{{argument type 'Incomplete' is incomplete}}
x.hidden_by_incomplete_return_value(10); // expected-error{{calling 'hidden_by_incomplete_return_value' with incomplete return type 'Incomplete'}}
deprec2(0);
overloaded(x);
default_argument(0);
default_argument(1, 2); // expected-error{{no matching function for call to 'default_argument'}}
default_argument_promotion(0);
default_argument_promotion(1, 2); // expected-error{{no matching function for call to 'default_argument_promotion'}}
int i = x(1); // expected-error{{no matching function for call to object of type 'X'}}
Nothing n;
typedep(0); // expected-error{{no matching function for call to 'typedep'}}
typedep(1);
typedep(n); // expected-note{{in instantiation of function template specialization 'typedep<Nothing>' requested here}}
}
template <typename T> class C {
void f() __attribute__((enable_if(T::expr == 0, ""))) {}
void g() { f(); }
};
int fn3(bool b) __attribute__((enable_if(b, ""))); // FIXME: This test should net 0 error messages.
template <class T> void test3() {
fn3(sizeof(T) == 1); // expected-error{{no matching function for call to 'fn3'}} expected-note@-2{{candidate disabled}}
}
template <typename T>
struct Y {
T h(int n, int m = 0) __attribute__((enable_if(m == 0, "chosen when 'm' is zero"))); // expected-note{{candidate disabled: chosen when 'm' is zero}}
};
void test4() {
Y<int> y;
int t0 = y.h(0);
int t1 = y.h(1, 2); // expected-error{{no matching member function for call to 'h'}}
}
// FIXME: issue an error (without instantiation) because ::h(T()) is not
// convertible to bool, because return types aren't overloadable.
void h(int);
template <typename T> void outer() {
void local_function() __attribute__((enable_if(::h(T()), "")));
local_function(); // expected-error{{no matching function for call to 'local_function'}} expected-note@-1{{candidate disabled}}
};
namespace PR20988 {
struct Integer {
Integer(int);
};
int fn1(const Integer &) __attribute__((enable_if(true, "")));
template <class T> void test1() {
int &expr = T::expr();
fn1(expr);
}
int fn2(const Integer &) __attribute__((enable_if(false, ""))); // expected-note{{candidate disabled}}
template <class T> void test2() {
int &expr = T::expr();
fn2(expr); // expected-error{{no matching function for call to 'fn2'}}
}
int fn3(bool b) __attribute__((enable_if(b, ""))); // FIXME: This test should net 0 error messages.
template <class T> void test3() {
fn3(sizeof(T) == 1); // expected-error{{no matching function for call to 'fn3'}} expected-note@-2{{candidate disabled}}
}
}
namespace FnPtrs {
int ovlFoo(int m) __attribute__((enable_if(m > 0, "")));
int ovlFoo(int m);
void test() {
// Assignment gives us a different code path than declarations, and `&foo`
// gives us a different code path than `foo`
int (*p)(int) = ovlFoo;
int (*p2)(int) = &ovlFoo;
int (*a)(int);
a = ovlFoo;
a = &ovlFoo;
}
int ovlBar(int) __attribute__((enable_if(true, "")));
int ovlBar(int m) __attribute__((enable_if(false, "")));
void test2() {
int (*p)(int) = ovlBar;
int (*p2)(int) = &ovlBar;
int (*a)(int);
a = ovlBar;
a = &ovlBar;
}
int ovlConflict(int m) __attribute__((enable_if(true, "")));
int ovlConflict(int m) __attribute__((enable_if(1, "")));
void test3() {
int (*p)(int) = ovlConflict; // expected-error{{address of overloaded function 'ovlConflict' is ambiguous}} expected-note@191{{candidate function}} expected-note@192{{candidate function}}
int (*p2)(int) = &ovlConflict; // expected-error{{address of overloaded function 'ovlConflict' is ambiguous}} expected-note@191{{candidate function}} expected-note@192{{candidate function}}
int (*a)(int);
a = ovlConflict; // expected-error{{assigning to 'int (*)(int)' from incompatible type '<overloaded function type>'}} expected-note@191{{candidate function}} expected-note@192{{candidate function}}
a = &ovlConflict; // expected-error{{assigning to 'int (*)(int)' from incompatible type '<overloaded function type>'}} expected-note@191{{candidate function}} expected-note@192{{candidate function}}
}
template <typename T>
T templated(T m) __attribute__((enable_if(true, ""))) { return T(); }
template <typename T>
T templated(T m) __attribute__((enable_if(false, ""))) { return T(); }
void test4() {
int (*p)(int) = templated<int>;
int (*p2)(int) = &templated<int>;
int (*a)(int);
a = templated<int>;
a = &templated<int>;
}
template <typename T>
T templatedBar(T m) __attribute__((enable_if(m > 0, ""))) { return T(); }
void test5() {
int (*p)(int) = templatedBar<int>; // expected-error{{address of overloaded function 'templatedBar' does not match required type 'int (int)'}} expected-note@214{{candidate function made ineligible by enable_if}}
int (*p2)(int) = &templatedBar<int>; // expected-error{{address of overloaded function 'templatedBar' does not match required type 'int (int)'}} expected-note@214{{candidate function made ineligible by enable_if}}
int (*a)(int);
a = templatedBar<int>; // expected-error{{assigning to 'int (*)(int)' from incompatible type '<overloaded function type>'}} expected-note@214{{candidate function made ineligible by enable_if}}
a = &templatedBar<int>; // expected-error{{assigning to 'int (*)(int)' from incompatible type '<overloaded function type>'}} expected-note@214{{candidate function made ineligible by enable_if}}
}
template <typename T>
T templatedConflict(T m) __attribute__((enable_if(false, ""))) { return T(); }
template <typename T>
T templatedConflict(T m) __attribute__((enable_if(true, ""))) { return T(); }
template <typename T>
T templatedConflict(T m) __attribute__((enable_if(1, ""))) { return T(); }
void test6() {
int (*p)(int) = templatedConflict<int>; // expected-error{{address of overloaded function 'templatedConflict' is ambiguous}} expected-note@224{{candidate function made ineligible by enable_if}} expected-note@226{{candidate function}} expected-note@228{{candidate function}}
int (*p0)(int) = &templatedConflict<int>; // expected-error{{address of overloaded function 'templatedConflict' is ambiguous}} expected-note@224{{candidate function made ineligible by enable_if}} expected-note@226{{candidate function}} expected-note@228{{candidate function}}
int (*a)(int);
a = templatedConflict<int>; // expected-error{{assigning to 'int (*)(int)' from incompatible type '<overloaded function type>'}} expected-note@226{{candidate function}} expected-note@228{{candidate function}}
a = &templatedConflict<int>; // expected-error{{assigning to 'int (*)(int)' from incompatible type '<overloaded function type>'}} expected-note@226{{candidate function}} expected-note@228{{candidate function}}
}
int ovlNoCandidate(int m) __attribute__((enable_if(false, "")));
int ovlNoCandidate(int m) __attribute__((enable_if(0, "")));
void test7() {
int (*p)(int) = ovlNoCandidate; // expected-error{{address of overloaded function 'ovlNoCandidate' does not match required type}} expected-note@237{{made ineligible by enable_if}} expected-note@238{{made ineligible by enable_if}}
int (*p2)(int) = &ovlNoCandidate; // expected-error{{address of overloaded function 'ovlNoCandidate' does not match required type}} expected-note@237{{made ineligible by enable_if}} expected-note@238{{made ineligible by enable_if}}
int (*a)(int);
a = ovlNoCandidate; // expected-error{{assigning to 'int (*)(int)' from incompatible type '<overloaded function type>'}} expected-note@237{{made ineligible by enable_if}} expected-note@238{{made ineligible by enable_if}}
a = &ovlNoCandidate; // expected-error{{assigning to 'int (*)(int)' from incompatible type '<overloaded function type>'}} expected-note@237{{made ineligible by enable_if}} expected-note@238{{made ineligible by enable_if}}
}
int noOvlNoCandidate(int m) __attribute__((enable_if(false, "")));
void test8() {
int (*p)(int) = noOvlNoCandidate; // expected-error{{cannot take address of function 'noOvlNoCandidate' because it has one or more non-tautological enable_if conditions}}
int (*p2)(int) = &noOvlNoCandidate; // expected-error{{cannot take address of function 'noOvlNoCandidate' because it has one or more non-tautological enable_if conditions}}
int (*a)(int);
a = noOvlNoCandidate; // expected-error{{cannot take address of function 'noOvlNoCandidate' because it has one or more non-tautological enable_if conditions}}
a = &noOvlNoCandidate; // expected-error{{cannot take address of function 'noOvlNoCandidate' because it has one or more non-tautological enable_if conditions}}
}
}
namespace casting {
using VoidFnTy = void (*)();
void foo(void *c) __attribute__((enable_if(0, "")));
void foo(int *c) __attribute__((enable_if(c, "")));
void foo(char *c) __attribute__((enable_if(1, "")));
void testIt() {
auto A = reinterpret_cast<VoidFnTy>(foo);
auto AAmp = reinterpret_cast<VoidFnTy>(&foo);
using VoidFooTy = void (*)(void *);
auto B = reinterpret_cast<VoidFooTy>(foo);
auto BAmp = reinterpret_cast<VoidFooTy>(&foo);
using IntFooTy = void (*)(int *);
auto C = reinterpret_cast<IntFooTy>(foo);
auto CAmp = reinterpret_cast<IntFooTy>(&foo);
using CharFooTy = void (*)(void *);
auto D = reinterpret_cast<CharFooTy>(foo);
auto DAmp = reinterpret_cast<CharFooTy>(&foo);
}
void testItCStyle() {
auto A = (VoidFnTy)foo;
auto AAmp = (VoidFnTy)&foo;
using VoidFooTy = void (*)(void *);
auto B = (VoidFooTy)foo;
auto BAmp = (VoidFooTy)&foo;
using IntFooTy = void (*)(int *);
auto C = (IntFooTy)foo;
auto CAmp = (IntFooTy)&foo;
using CharFooTy = void (*)(void *);
auto D = (CharFooTy)foo;
auto DAmp = (CharFooTy)&foo;
}
}
namespace casting_templates {
template <typename T> void foo(T) {} // expected-note 4 {{candidate function}}
void foo(int *c) __attribute__((enable_if(c, ""))); //expected-note 4 {{candidate function}}
void foo(char *c) __attribute__((enable_if(c, ""))); //expected-note 4 {{candidate function}}
void testIt() {
using IntFooTy = void (*)(int *);
auto A = reinterpret_cast<IntFooTy>(foo); // expected-error{{reinterpret_cast cannot resolve overloaded function 'foo' to type}}
auto ARef = reinterpret_cast<IntFooTy>(&foo); // expected-error{{reinterpret_cast cannot resolve overloaded function 'foo' to type}}
auto AExplicit = reinterpret_cast<IntFooTy>(foo<int*>);
using CharFooTy = void (*)(char *);
auto B = reinterpret_cast<CharFooTy>(foo); // expected-error{{reinterpret_cast cannot resolve overloaded function 'foo' to type}}
auto BRef = reinterpret_cast<CharFooTy>(&foo); // expected-error{{reinterpret_cast cannot resolve overloaded function 'foo' to type}}
auto BExplicit = reinterpret_cast<CharFooTy>(foo<char*>);
}
void testItCStyle() {
// constexpr is usable here because all of these should become static_casts.
using IntFooTy = void (*)(int *);
constexpr auto A = (IntFooTy)foo;
constexpr auto ARef = (IntFooTy)&foo;
constexpr auto AExplicit = (IntFooTy)foo<int*>;
using CharFooTy = void (*)(char *);
constexpr auto B = (CharFooTy)foo;
constexpr auto BRef = (CharFooTy)&foo;
constexpr auto BExplicit = (CharFooTy)foo<char*>;
static_assert(A == ARef && ARef == AExplicit, "");
static_assert(B == BRef && BRef == BExplicit, "");
}
}
namespace multiple_matches {
using NoMatchTy = void (*)();
void foo(float *c); //expected-note 4 {{candidate function}}
void foo(int *c) __attribute__((enable_if(1, ""))); //expected-note 4 {{candidate function}}
void foo(char *c) __attribute__((enable_if(1, ""))); //expected-note 4 {{candidate function}}
void testIt() {
auto A = reinterpret_cast<NoMatchTy>(foo); // expected-error{{reinterpret_cast cannot resolve overloaded function 'foo' to type}}
auto ARef = reinterpret_cast<NoMatchTy>(&foo); // expected-error{{reinterpret_cast cannot resolve overloaded function 'foo' to type}}
auto C = (NoMatchTy)foo; // expected-error{{address of overloaded function 'foo' does not match required type 'void ()'}}
auto CRef = (NoMatchTy)&foo; // expected-error{{address of overloaded function 'foo' does not match required type 'void ()'}}
}
}
namespace PR27122 {
// (slightly reduced) code that motivated the bug...
namespace ns {
void Function(int num)
__attribute__((enable_if(num != 0, "")));
void Function(int num, int a0)
__attribute__((enable_if(num != 1, "")));
} // namespace ns
using ns::Function; // expected-note 3{{declared here}}
void Run() {
Functioon(0); // expected-error{{use of undeclared identifier}} expected-error{{too few arguments}}
Functioon(0, 1); // expected-error{{use of undeclared identifier}}
Functioon(0, 1, 2); // expected-error{{use of undeclared identifier}}
}
// Extra tests
void regularEnableIf(int a) __attribute__((enable_if(a, ""))); // expected-note 3{{declared here}} expected-note 3{{candidate function not viable}}
void runRegularEnableIf() {
regularEnableIf(0, 2); // expected-error{{no matching function}}
regularEnableIf(1, 2); // expected-error{{no matching function}}
regularEnableIf(); // expected-error{{no matching function}}
// Test without getting overload resolution involved
::PR27122::regularEnableIf(0, 2); // expected-error{{too many arguments}}
::PR27122::regularEnableIf(1, 2); // expected-error{{too many arguments}}
::PR27122::regularEnableIf(); // expected-error{{too few arguments}}
}
struct Foo {
void bar(int i) __attribute__((enable_if(i, ""))); // expected-note 2{{declared here}}
};
void runFoo() {
Foo f;
f.bar(); // expected-error{{too few arguments}}
f.bar(1, 2); // expected-error{{too many arguments}}
}
}
// Ideally, we should be able to handle value-dependent expressions sanely.
// Sadly, that isn't the case at the moment.
namespace dependent {
int error(int N) __attribute__((enable_if(N, ""))); // expected-note{{candidate disabled}}
int error(int N) __attribute__((enable_if(!N, ""))); // expected-note{{candidate disabled}}
template <int N> int callUnavailable() {
return error(N); // expected-error{{no matching function for call to 'error'}}
}
constexpr int noError(int N) __attribute__((enable_if(N, ""))) { return -1; }
constexpr int noError(int N) __attribute__((enable_if(!N, ""))) { return -1; }
constexpr int noError(int N) { return 0; }
template <int N>
constexpr int callNoError() { return noError(N); }
static_assert(callNoError<0>() == 0, "");
static_assert(callNoError<1>() == 0, "");
template <int N> constexpr int templated() __attribute__((enable_if(N, ""))) {
return 1;
}
constexpr int A = templated<0>(); // expected-error{{no matching function for call to 'templated'}} expected-note@-4{{candidate disabled}}
static_assert(templated<1>() == 1, "");
template <int N> constexpr int callTemplated() { return templated<N>(); }
constexpr int B = 10 + // the carat for the error should be pointing to the problematic call (on the next line), not here.
callTemplated<0>(); // expected-error{{initialized by a constant expression}} expected-error@-3{{no matching function for call to 'templated'}} expected-note{{in instantiation of function template}} expected-note@-10{{candidate disabled}}
static_assert(callTemplated<1>() == 1, "");
}
namespace variadic {
void foo(int a, int b = 0, ...) __attribute__((enable_if(a && b, ""))); // expected-note 6{{disabled}}
void testFoo() {
foo(1, 1);
foo(1, 1, 2);
foo(1, 1, 2, 3);
foo(1, 0); // expected-error{{no matching}}
foo(1, 0, 2); // expected-error{{no matching}}
foo(1, 0, 2, 3); // expected-error{{no matching}}
int m;
foo(1, 1);
foo(1, 1, m);
foo(1, 1, m, 3);
foo(1, 0); // expected-error{{no matching}}
foo(1, 0, m); // expected-error{{no matching}}
foo(1, 0, m, 3); // expected-error{{no matching}}
}
}
// Tests that we emit errors at the point of the method call, rather than the
// beginning of the expression that happens to be a member call.
namespace member_loc {
struct Foo { void bar() __attribute__((enable_if(0, ""))); }; // expected-note{{disabled}}
void testFoo() {
Foo()
.bar(); // expected-error{{no matching member function}}
}
}
// Prior bug: we wouldn't properly convert conditions to bools when
// instantiating templates in some cases.
namespace template_instantiation {
template <typename T>
struct Foo {
void bar(int a) __attribute__((enable_if(a, ""))); // expected-note{{disabled}}
};
void runFoo() {
Foo<double>().bar(0); // expected-error{{no matching}}
Foo<double>().bar(1);
}
}
namespace instantiate_constexpr_in_enable_if {
template<typename T> struct X {
static constexpr bool ok() { return true; }
void f() __attribute__((enable_if(ok(), "")));
};
void g() { X<int>().f(); }
}
namespace PR31934 {
int foo(int a) __attribute__((enable_if(a, "")));
int runFn(int (&)(int));
void run() {
{
int (&bar)(int) = foo; // expected-error{{cannot take address of function 'foo'}}
int baz = runFn(foo); // expected-error{{cannot take address of function 'foo'}}
}
{
int (&bar)(int) = (foo); // expected-error{{cannot take address of function 'foo'}}
int baz = runFn((foo)); // expected-error{{cannot take address of function 'foo'}}
}
{
int (&bar)(int) = static_cast<int (&)(int)>(foo); // expected-error{{cannot take address of function 'foo'}}
int baz = runFn(static_cast<int (&)(int)>(foo)); // expected-error{{cannot take address of function 'foo'}}
}
{
int (&bar)(int) = static_cast<int (&)(int)>((foo)); // expected-error{{cannot take address of function 'foo'}}
int baz = runFn(static_cast<int (&)(int)>((foo))); // expected-error{{cannot take address of function 'foo'}}
}
}
}
namespace TypeOfFn {
template <typename T, typename U>
struct is_same;
template <typename T> struct is_same<T, T> {
enum { value = 1 };
};
void foo(int a) __attribute__((enable_if(a, "")));
void foo(float a) __attribute__((enable_if(1, "")));
static_assert(is_same<__typeof__(foo)*, decltype(&foo)>::value, "");
}
namespace InConstantContext {
void foo(const char *s) __attribute__((enable_if(((void)__builtin_constant_p(*s), true), "trap"))) {}
void test() {
InConstantContext::foo("abc");
}
} // namespace InConstantContext
namespace StringLiteralDetector {
void need_string_literal(const char *p) __attribute__((enable_if(__builtin_constant_p(p), "argument is not a string literal"))); // expected-note 2{{not a string literal}}
void test(const char *unknown) {
need_string_literal("foo");
need_string_literal(unknown); // expected-error {{no matching function}}
constexpr char str[] = "bar";
need_string_literal(str); // expected-error {{no matching function}}
}
}
namespace IgnoreUnusedArgSideEffects {
struct A { ~A(); };
void f(A a, bool b) __attribute__((enable_if(b, ""))); // expected-note 2-3{{disabled}}
void test() {
f(A(), true);
f(A(), false); // expected-error {{no matching function}}
int n;
f((n = 1, A()), true);
f(A(), (n = 1, true)); // expected-error {{no matching function}}
f(A(), (A(), true));
}
#if __cplusplus > 201702L
struct B { constexpr ~B() {} bool b; };
void g(B b) __attribute__((enable_if(b.b, ""))); // expected-note {{disabled}}
void test2() {
g(B{true});
g(B{false}); // expected-error {{no matching function}}
f(A(), B{true}.b);
f(A(), B{false}.b); // expected-error {{no matching function}}
}
// First condition is non-constant due to non-constexpr destructor of A.
int &h() __attribute__((enable_if((A(), true), "")));
float &h() __attribute__((enable_if((B(), true), "")));
float &x = h();
#endif
}
namespace DefaultArgs {
void f(int n = __builtin_LINE()) __attribute__((enable_if(n == 12345, "only callable on line 12345"))); // expected-note {{only callable on line 12345}}
void g() { f(); } // expected-error {{no matching function}}
#line 12345
void h() { f(); }
template<typename T> void x(int n = T()) __attribute__((enable_if(n == 0, ""))) {} // expected-note {{candidate}}
void y() { x<int>(); }
struct Z { constexpr operator int() const { return 1; } };
void z() { x<Z>(); } // expected-error {{no matching function}}
}