diff options
Diffstat (limited to 'gcc/testsuite/g++.dg/template/sfinae5.C')
-rw-r--r-- | gcc/testsuite/g++.dg/template/sfinae5.C | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/template/sfinae5.C b/gcc/testsuite/g++.dg/template/sfinae5.C new file mode 100644 index 000000000..516e5cc85 --- /dev/null +++ b/gcc/testsuite/g++.dg/template/sfinae5.C @@ -0,0 +1,47 @@ +// DR 339 +// +// Test of the use of member functions with SFINAE +typedef char yes_type; +struct no_type { char data[2]; }; + +template<typename T> T create_a(); + +template<bool, typename T = void> struct enable_if { typedef T type; }; +template<typename T> struct enable_if<false, T> { }; + +template<typename T> + typename enable_if<(sizeof(create_a<T>().foo(), 1) > 0), + yes_type>::type + check_has_member_foo(const volatile T&); + +no_type check_has_member_foo(...); + +template<typename T> +struct has_foo +{ + static const bool value = + (sizeof(check_has_member_foo(create_a<T const&>())) == sizeof(yes_type)); +}; + +struct X { }; +struct Y { + void foo(); +}; +struct Z { + void foo(int); +}; + +struct A { + int foo; +}; + +struct B { + static int foo(); +}; + +int a1[has_foo<X>::value? -1 : 1]; +int a2[has_foo<Y>::value? 1 : -1]; +int a3[has_foo<Z>::value? -1 : 1]; +int a4[has_foo<int>::value? -1 : 1]; +int a5[has_foo<A>::value? -1 : 1]; +int a6[has_foo<B>::value? 1 : -1]; |