From b3d1d1f4fff816423ea8c652d8d849aacc4c6ce8 Mon Sep 17 00:00:00 2001
From: Louis Dionne <ldionne.2@gmail.com>
Date: Mon, 14 Dec 2020 16:58:52 -0500
Subject: [PATCH] [libc++] Remove unnecessary static assertion in
 allocate_shared

Checking that `T` is constructible from `Args...` is technically not
required by the Standard, although any implementation will obviously
error out if that's not satisfied. However, this check is incompatible
with using Allocator construction in the control block (upcoming change
as part of implementing P0674), so I'm removing it now to reduce the
upcoming diff as much as possible.

Differential Revision: https://reviews.llvm.org/D93246
---
 libcxx/include/memory                              |  2 --
 .../allocate_shared.protected.verify.cpp           | 34 ----------------------
 .../make_shared.protected.verify.cpp               | 31 --------------------
 3 files changed, 67 deletions(-)
 delete mode 100644 libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared.protected.verify.cpp
 delete mode 100644 libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.protected.verify.cpp

diff --git a/libcxx/include/memory b/libcxx/include/memory
index c676cd01c..4167f01 100644
--- a/libcxx/include/memory
+++ b/libcxx/include/memory
@@ -3307,8 +3307,6 @@ template<class _Tp, class _Alloc, class ..._Args, class = _EnableIf<!is_array<_T
 _LIBCPP_HIDE_FROM_ABI
 shared_ptr<_Tp> allocate_shared(const _Alloc& __a, _Args&& ...__args)
 {
-    static_assert(is_constructible<_Tp, _Args...>::value,
-        "allocate_shared/make_shared: the type is not constructible from the provided arguments");
     using _ControlBlock = __shared_ptr_emplace<_Tp, _Alloc>;
     using _ControlBlockAllocator = typename __allocator_traits_rebind<_Alloc, _ControlBlock>::type;
     __allocation_guard<_ControlBlockAllocator> __guard(__a, 1);
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared.protected.verify.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared.protected.verify.cpp
deleted file mode 100644
index fbd7bfa..0000000
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared.protected.verify.cpp
+++ /dev/null
@@ -1,34 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// GCC 5 does not evaluate static assertions dependent on a template parameter.
-// UNSUPPORTED: gcc-5
-
-// <memory>
-
-// shared_ptr
-
-// template<class T, class A, class... Args>
-//    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
-
-#include <memory>
-
-#include "test_macros.h"
-
-struct S {
-protected:
-   S () {};  // ctor is protected
-};
-
-int main(int, char**) {
-    typedef std::allocator<S> A;
-    A a;
-    std::shared_ptr<S> p = std::allocate_shared<S, A>(a); // expected-error@memory:* {{static_assert failed due to requirement 'is_constructible<S>::value}}
-
-    return 0;
-}
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.protected.verify.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.protected.verify.cpp
deleted file mode 100644
index a2b6e98..0000000
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.protected.verify.cpp
+++ /dev/null
@@ -1,31 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// GCC 5 does not evaluate static assertions dependent on a template parameter.
-// UNSUPPORTED: gcc-5
-
-// <memory>
-
-// shared_ptr
-
-// template<class T, class... Args> shared_ptr<T> make_shared(Args&&... args);
-
-#include <memory>
-
-#include "test_macros.h"
-
-struct S {
-protected:
-   S () {};  // ctor is protected
-};
-
-int main(int, char**) {
-  std::shared_ptr<S> p = std::make_shared<S>(); // expected-error@memory:* {{static_assert failed due to requirement 'is_constructible<S>::value}}
-
-  return 0;
-}
-- 
2.7.4