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      <base href="https://bugs.llvm.org/">
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - MSVC Compatibility: Implement intrinsics for P0466R5 - Layout-compatibility and Pointer-interconvertibility Traits"
   href="https://bugs.llvm.org/show_bug.cgi?id=48860">48860</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>MSVC Compatibility: Implement intrinsics for P0466R5 - Layout-compatibility and Pointer-interconvertibility Traits
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>clang
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>11.0
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Windows NT
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>C++2a
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedclangbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>mahmoud.g.saleh@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>blitzrakete@gmail.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
          </td>
        </tr></table>
      <p>
        <div>
        <pre>MSVC recently implemented the following intrinsics needed for P0466R5
Layout-compatibility and Pointer-interconvertibility Traits:

* __builtin_is_layout_compatible
* __builtin_is_pointer_interconvertible_base_of
* __builtin_is_pointer_interconvertible_with_class
* __builtin_is_corresponding_member

MSVC STL is planning to use them in <type_traits> as follows (PR:
<a href="https://github.com/microsoft/STL/pull/1575">https://github.com/microsoft/STL/pull/1575</a>):

// STRUCT TEMPLATE is_layout_compatible
template <class _Ty1, class _Ty2>
struct is_layout_compatible :
bool_constant<__builtin_is_layout_compatible(_Ty1, _Ty2)> {};

template <class _Ty1, class _Ty2>
inline constexpr bool is_layout_compatible_v =
__builtin_is_layout_compatible(_Ty1, _Ty2);

// STRUCT TEMPLATE is_pointer_interconvertible_base_of
template <class _Base, class _Derived>
struct is_pointer_interconvertible_base_of
    : bool_constant<__builtin_is_pointer_interconvertible_base_of(_Base,
_Derived)> {};

template <class _Base, class _Derived>
inline constexpr bool is_pointer_interconvertible_base_of_v =
__builtin_is_pointer_interconvertible_base_of(
    _Base, _Derived);

// FUNCTION TEMPLATE is_pointer_interconvertible_with_class
template <class _ClassTy, class _MemberTy>
_NODISCARD constexpr bool is_pointer_interconvertible_with_class(_MemberTy
_ClassTy::*_Pm) noexcept {
    return __builtin_is_pointer_interconvertible_with_class(_ClassTy, _Pm);
}

// FUNCTION TEMPLATE is_corresponding_member
template <class _ClassTy1, class _ClassTy2, class _MemberTy1, class _MemberTy2>
_NODISCARD constexpr bool is_corresponding_member(_MemberTy1 _ClassTy1::*_Pm1,
_MemberTy2 _ClassTy2::*_Pm2) noexcept {
    return __builtin_is_corresponding_member(_ClassTy1, _ClassTy2, _Pm1, _Pm2);</pre>
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