[libc++] Move C++17 check around optional only in ObjC is_scalar test.

[zoecarver]

Summary

Check the std version around the use of optional in is_scalar Objective-C test instead of checking the whole file.

[zoecarver]

libcxx/test/libcxx/type_traits/is_scalar.objc.pass.mm

20

I'm using this because I'm not sure if it will work to include test_macros.h.

[ldionne]

libcxx/test/libcxx/type_traits/is_scalar.objc.pass.mm

36–37

You can actually remove this altogether, since I had added libcxx/test/libcxx/utilities/optional/block.objc.pass.mm at the time anyway. You should also rebase the patch on top of master.

[zoecarver]

• Remove std::optional test altogether because it's tested elsewhere

[zoecarver]

• Merge branch 'master' into fix/objc-is-scalar

[zoecarver]

Thanks @ldionne! Resolved by 7a0dc1a9e77d023871e166c9d2aecf9133ddf043.

libcxx/test/libcxx/type_traits/is_scalar.objc.pass.mm

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++98, c++03, c++11, c++14
+// UNSUPPORTED: c++98, c++03
 // REQUIRES: has-fblocks
 // ADDITIONAL_COMPILE_FLAGS: -fblocks
 
 // <type_traits>
 
 // std::is_scalar
 
 // Make sure we report that blocks are scalar types.
 
 #include <type_traits>
-#include <optional>
 
 struct Foo { };
 template <int> struct Arg { };
 
 static_assert(std::is_scalar<void (^)(void)>::value, "");
 static_assert(std::is_scalar<void (^)()>::value, "");
 static_assert(std::is_scalar<void (^)(Arg<0>)>::value, "");
 static_assert(std::is_scalar<void (^)(Arg<0>, Arg<1>)>::value, "");
 static_assert(std::is_scalar<void (^)(Arg<0>, Arg<1>, Arg<2>)>::value, "");
 static_assert(std::is_scalar<Foo (^)(void)>::value, "");
 static_assert(std::is_scalar<Foo (^)()>::value, "");
 static_assert(std::is_scalar<Foo (^)(Arg<0>)>::value, "");
 static_assert(std::is_scalar<Foo (^)(Arg<0>, Arg<1>)>::value, "");
 static_assert(std::is_scalar<Foo (^)(Arg<0>, Arg<1>, Arg<2>)>::value, "");
 
 
 int main(int, char**) {
-    // Make sure that std::optional can be used with a block, which is the
-    // underlying motivation for making blocks satisfy std::is_scalar.
-    std::optional<Foo (^)(Arg<0>)> opt; (void)opt;
     return 0;
 }