c++ - boost/thread.hpp 失败并显示 'clang++ -std=c++11 -stdlib=libc++'

Question

尝试使用 clang + libc++(C++11 模式)编译这一行时:

#include <boost/thread.hpp>

clang 发出以下错误:

In file included from test.cpp:1:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/thread.hpp:13:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/thread/thread.hpp:17:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/thread/pthread/thread_data.hpp:11:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/thread/locks.hpp:18:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/chrono/time_point.hpp:33:
/Users/yongwei/Programming/boost_1_52_0/boost/chrono/duration.hpp:353:49: error: 
  constexpr function never produces a constant expression
    static BOOST_CHRONO_LIB_CONSTEXPR float lowest() ...
                        ^
/Users/yongwei/Programming/boost_1_52_0/boost/chrono/duration.hpp:355:21: note: 
  non-constexpr function 'max' cannot be used in a constant expression
    return -(std::numeric_limits::max) ();
        ^
/usr/bin/../lib/c++/v1/limits:443:43: note: declared here
_LIBCPP_INLINE_VISIBILITY static type max() _NOEXCEPT {return ...
                      ^
In file included from test.cpp:1:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/thread.hpp:13:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/thread/thread.hpp:17:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/thread/pthread/thread_data.hpp:11:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/thread/locks.hpp:18:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/chrono/time_point.hpp:33:
/Users/yongwei/Programming/boost_1_52_0/boost/chrono/duration.hpp:361:50: error: 
  constexpr function never produces a constant expression
    static BOOST_CHRONO_LIB_CONSTEXPR double lowest() ...
                         ^
/Users/yongwei/Programming/boost_1_52_0/boost/chrono/duration.hpp:363:21: note: 
  non-constexpr function 'max' cannot be used in a constant expression
    return -(std::numeric_limits::max) ();
        ^
/usr/bin/../lib/c++/v1/limits:443:43: note: declared here
_LIBCPP_INLINE_VISIBILITY static type max() _NOEXCEPT {return ...
                      ^
In file included from test.cpp:1:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/thread.hpp:13:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/thread/thread.hpp:17:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/thread/pthread/thread_data.hpp:11:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/thread/locks.hpp:18:
In file included from /Users/yongwei/Programming/boost_1_52_0/boost/chrono/time_point.hpp:33:
/Users/yongwei/Programming/boost_1_52_0/boost/chrono/duration.hpp:369:55: error: 
  constexpr function never produces a constant expression
    static BOOST_CHRONO_LIB_CONSTEXPR long double lowest() ...
                          ^
/Users/yongwei/Programming/boost_1_52_0/boost/chrono/duration.hpp:371:21: note: 
  non-constexpr function 'max' cannot be used in a constant expression
    return -(std::numeric_limits::max)();
        ^
/usr/bin/../lib/c++/v1/limits:443:43: note: declared here
_LIBCPP_INLINE_VISIBILITY static type max() _NOEXCEPT {return ...
                      ^
3 errors generated.

在我看来，这是 libc++ 中的一个错误，因为 C++11 确实要求这些函数为 constexpr。

有人遇到过同样的问题吗？你知道有什么修复吗？

我的 clang 版本是:

Apple clang version 4.1 (tags/Apple/clang-421.11.66) (based on LLVM 3.1svn)
Target: x86_64-apple-darwin11.4.2
Thread model: posix

Answer 1

根据马克思的提示，我找到了解决方法。在这种情况下，定义 BOOST_NO_CXX11_NUMERIC_LIMITS 会有所帮助。所以这看起来确实是 libc++ 的不完整性。

根据 Howard Hinnant 的说法，这是 libc++ 的一个 bug，并且已经在 trunk 上修复了。然而，目前尚不清楚 Apple 何时可以将修复程序发布到 Xcode 中。我将暂时标记已回答的问题。

编辑:该问题已在 Apple LLVM 版本 4.2 (clang-425.0.28)(基于 LLVM 3.2svn)中修复。我当前的 Xcode 版本是 4.6.3。