Manually force the use of __decltype in C++03 with Clang 3.4.
<string> uses `decltype` in a way incompatible with `__typeof__`.
This is problematic when compiling <string> with Clang 3.4 because
even though it provides `__decltype` libc++ still used `__typeof__`
because clang 3.4 doesn't provide __is_identifier which libc++
uses to detect __decltype.
This patch manually detects Clang 3.4 and properly configures
for it.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@292833 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__config b/include/__config
index 9585f33..44f1344 100644
--- a/include/__config
+++ b/include/__config
@@ -109,6 +109,9 @@
#if defined(__clang__)
#define _LIBCPP_COMPILER_CLANG
+# ifndef __apple_build_version__
+# define _LIBCPP_CLANG_VER (__clang_major__ * 100 + __clang_minor__)
+# endif
#elif defined(__GNUC__)
#define _LIBCPP_COMPILER_GCC
#elif defined(_MSC_VER)
@@ -117,6 +120,10 @@
#define _LIBCPP_COMPILER_IBM
#endif
+#ifndef _LIBCPP_CLANG_VER
+#define _LIBCPP_CLANG_VER 0
+#endif
+
// FIXME: ABI detection should be done via compiler builtin macros. This
// is just a placeholder until Clang implements such macros. For now assume
// that Windows compilers pretending to be MSVC++ target the microsoft ABI.
@@ -754,7 +761,7 @@
#ifdef _LIBCPP_HAS_NO_DECLTYPE
// GCC 4.6 provides __decltype in all standard modes.
-#if __has_keyword(__decltype) || _GNUC_VER >= 406
+#if __has_keyword(__decltype) || _LIBCPP_CLANG_VER >= 304 || _GNUC_VER >= 406
# define decltype(__x) __decltype(__x)
#else
# define decltype(__x) __typeof__(__x)
