[libc++][NFC] Remove workaround for variadic templates in C++03

[ldionne]

Summary

That's not necessary anymore, since we always build the dylib with
C++11 capabilities nowadays.

[• Quuxplusone]

LGTM % whitespace comment, FWIW.

libcxx/src/locale.cpp

84–86

As in that other recent review, please prefer libc++ style: class... Args and Args... args.

[ldionne]

The windows job failed due to "no space left on device", so I'll assume this passed.

libcxx/src/locale.cpp

84–86

There's no "libc++" style in this case. I get 652 hits for class ..., and 940 hits for class..., so there's no clearly consistent approach here. If you can explain to me why class... is better, I'll change it.

[• Quuxplusone]

libcxx/src/locale.cpp

84–86

If you can explain to me why class... is better, I'll change it.

Only the stylistic argument that it's "what we've always done" (and what you've done as recently as D101277, although I guess that started out as Chris's patch). I do see now that we've got a mix in libc++; class... predominates but not overwhelmingly. Likewise Ts&&... ts mildly predominates over Ts&& ...ts (and overwhelmingly over Ts &&...ts, of course; we also have 8 instances of Ts &&... ts).

The Standard draft itself does use class... Ts (and T& t, and west const) as its house style:

$ git grep 'class[.][.][.] [A-Z]' | wc -l
     424
$ git grep 'class [.][.][.][A-Z]' | wc -l
       1
$ git grep 'typename[.][.][.] [A-Z]' | wc -l
      10
$ git grep 'typename [.][.][.][A-Z]' | wc -l
       5

Arguably, <class... Ts> has the minor benefit that when you textually delete the trailing parameter name, you get <class...>, which we do overwhelmingly prefer over <class ...>:

$ git grep '[^ ][.][.][.]>' libcxx/include/ | wc -l
     778
$ git grep '[ ][.][.][.]>' libcxx/include/ | wc -l
       9

Anyway, I'll try to stop commenting on this. I really just noticed you doing it on the patch the other day; I'd never noticed it before this week.

libcxx/src/locale.cpp

 
 namespace {
 
 struct release
 {
     void operator()(locale::facet* p) {p->__release_shared();}
 };
 
-template <class T, class A0>
-inline
-T&
-make(A0 a0)
-{
-    static typename aligned_storage<sizeof(T)>::type buf;
-    auto *obj = ::new (&buf) T(a0);
-    return *obj;
-}
-
-template <class T, class A0, class A1>
-inline
-T&
-make(A0 a0, A1 a1)
-{
-    static typename aligned_storage<sizeof(T)>::type buf;
-    ::new (&buf) T(a0, a1);
-    return *reinterpret_cast<T*>(&buf);
-}
-
-template <class T, class A0, class A1, class A2>
-inline
-T&
-make(A0 a0, A1 a1, A2 a2)
+template <class T, class ...Args>
+T& make(Args ...args)
 {
     static typename aligned_storage<sizeof(T)>::type buf;
-    auto *obj = ::new (&buf) T(a0, a1, a2);
+    auto *obj = ::new (&buf) T(args...);
     return *obj;
 }
 
 template <typename T, size_t N>
 inline
 _LIBCPP_CONSTEXPR
 size_t
 countof(const T (&)[N])