c++ - 上的 clang++ 错误

Question

编译包含 <experimental/any> 的代码时出现错误.

main.cpp 中的代码:

#include <experimental/any>
int main() { }

编译这个(clang 版本是 3.9):

clang++ main.cpp -o main -std=c++1z

编译后报错:

In file included from main.cpp:2:
/usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/experimental/any:364:34: error: 
      no template named '__any_caster'; did you mean 'any_cast'?
        return static_cast<_ValueType*>(__any_caster<_ValueType>(__any));
                                        ^
/usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/experimental/any:361:30: note: 
      'any_cast' declared here
    inline const _ValueType* any_cast(const any* __any) noexcept
                             ^
/usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/experimental/any:372:34: error: 
      no template named '__any_caster'; did you mean 'any_cast'?
        return static_cast<_ValueType*>(__any_caster<_ValueType>(__any));
                                        ^
/usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/experimental/any:369:24: note: 
      'any_cast' declared here
    inline _ValueType* any_cast(any* __any) noexcept
                       ^
2 errors generated.

Answer 1

作为@chris在comments中提到:

You could try with libc++. Perhaps there's an incompatibility with Clang in libstdc++'s new header.

事实证明这是真的。 Clang 3.9 仍处于实验阶段，因此它使用实验性 header ，包括实验性 C++ 标准库。默认情况下，它由 GCC 提供，因此 GCC 实现与 Clang 实现之间存在不兼容问题。