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Fix std::byte namespace declaration
- From: François Dumont <frs dot dumont at gmail dot com>
- To: "libstdc++ at gcc dot gnu dot org" <libstdc++ at gcc dot gnu dot org>, gcc-patches <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 18 Oct 2018 22:12:44 +0200
- Subject: Fix std::byte namespace declaration
Current build of libstdc++ with --enable-symvers=gnu-versioned-namespace
fails (at least under Linux) because of:
In file included from
/home/fdt/dev/gcc/build_versioned_ns/x86_64-pc-linux-gnu/libstdc++-v3/include/memory_resource:39,
from
../../../../../git/libstdc++-v3/src/c++17/memory_resource.cc:25:
/home/fdt/dev/gcc/build_versioned_ns/x86_64-pc-linux-gnu/libstdc++-v3/include/cstddef:71:59:
error: la référence à « byte » est ambiguë
71 | template<> struct __byte_operand<bool> { using __type = byte; };
| ^~~~
In file included from
/home/fdt/dev/gcc/build_versioned_ns/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/stl_algobase.h:61,
from
/home/fdt/dev/gcc/build_versioned_ns/x86_64-pc-linux-gnu/libstdc++-v3/include/memory:62,
from
/home/fdt/dev/gcc/build_versioned_ns/x86_64-pc-linux-gnu/libstdc++-v3/include/memory_resource:37,
from
../../../../../git/libstdc++-v3/src/c++17/memory_resource.cc:25:
/home/fdt/dev/gcc/build_versioned_ns/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/cpp_type_traits.h:395:30:
note: les candidats sont : « enum class std::__8::byte »
395 | enum class byte : unsigned char;
| ^~~~
In file included from
/home/fdt/dev/gcc/build_versioned_ns/x86_64-pc-linux-gnu/libstdc++-v3/include/memory_resource:39,
from
../../../../../git/libstdc++-v3/src/c++17/memory_resource.cc:25:
/home/fdt/dev/gcc/build_versioned_ns/x86_64-pc-linux-gnu/libstdc++-v3/include/cstddef:68:14:
note: « enum class std::byte »
68 | enum class byte : unsigned char {};
| ^~~~
I think the issue if that std::byte declaration in cpp_type_traits.h has
been done in versioned namespace, so the attached patch.
* include/bits/cpp_type_traits.h (std::byte): Move outside versioned
namespace.
Tested under Linux x86_64.
Ok to commit ?
François
diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h b/libstdc++-v3/include/bits/cpp_type_traits.h
index 960d469f412..fa7fc7564c2 100644
--- a/libstdc++-v3/include/bits/cpp_type_traits.h
+++ b/libstdc++-v3/include/bits/cpp_type_traits.h
@@ -68,6 +68,10 @@ extern "C++" {
namespace std _GLIBCXX_VISIBILITY(default)
{
+#if __cplusplus >= 201703L
+ enum class byte : unsigned char;
+#endif
+
_GLIBCXX_BEGIN_NAMESPACE_VERSION
struct __true_type { };
@@ -392,8 +396,6 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3)
};
#if __cplusplus >= 201703L
- enum class byte : unsigned char;
-
template<>
struct __is_byte<byte>
{