Re: [PATCH 1/5] std::latch: reduce internal implementation from ptrdiff_t to int

[Jonathan Wakely via Gcc-patches]

On 26/02/21 07:59 -0800, Thiago Macieira via Libstdc++ wrote:

ints can be used as futex on Linux. ptrdiff_t on 64-bit Linux can't.

Yes, we should do this for GCC 11.

libstdc++-v3/include/std/latch | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/std/latch b/libstdc++-v3/include/std/latch
index ef8c301e5e9..156aea5c5e5 100644
--- a/libstdc++-v3/include/std/latch
+++ b/libstdc++-v3/include/std/latch
@@ -48,7 +48,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
  public:
    static constexpr ptrdiff_t
    max() noexcept
-    { return __gnu_cxx::__int_traits<ptrdiff_t>::__max; }
+    { return __gnu_cxx::__int_traits<int>::__max; }

    constexpr explicit latch(ptrdiff_t __expected) noexcept
      : _M_a(__expected) { }
@@ -85,7 +85,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    }

  private:
-    alignas(__alignof__(ptrdiff_t)) ptrdiff_t _M_a;
+    alignas(__alignof__(int)) int _M_a;
  };
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
--
2.30.1