Viewing file:  sfinae11.C (1.17 KB) -rw-r--r--
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// PR c++/48468
// { dg-do compile { target c++11 } }
// { dg-prune-output "note" }
template<class T>
T&& declval() noexcept;
template< class T >
inline void f1( T& x ) noexcept( noexcept( declval<T&>().foo() ) ) // { dg-error "Z" }
{
x.foo();
}
template< class T,
bool Noexcept = noexcept( declval<T&>().foo() ) // { dg-error "no member|not convert" }
>
inline void f2( T& x ) noexcept( Noexcept )
{
x.foo();
}
// a common and trivial mistake
template< class T >
inline void f3( T& x ) noexcept( declval<T&>().foo() ) // { dg-error "Z" }
{
x.foo();
}
struct X
{
void foo();
};
struct Y
{
void foo() noexcept;
};
struct Z {};
int main()
{
X x; Y y; Z z;
static_assert( !noexcept( f1(x) ), "OK." );
static_assert( !noexcept( f2(x) ), "OK." );
// static_assert( !noexcept( f3(x) ), "shall be ill-formed(OK)." );
static_assert( noexcept( f1(y) ), "OK." );
static_assert( noexcept( f2(y) ), "OK." );
// static_assert( noexcept( f3(y) ), "shall be ill-formed(OK)." );
noexcept( f1(z) ); // { dg-message "required" }
static_assert( noexcept( f2(z) ), "shall be ill-formed." ); // { dg-error "no match" }
noexcept( f3(z) ); // { dg-message "required" }
}
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