在学习有关对齐的问题等等，我意识到，我的实现G ++ 4.9（MacPorts的OS X）不具有的std ::对齐支持。如果我尝试编译（用 -std = C ++ 11 ）的http://www.cplusplus.com/reference/memory/align/

While learning about alignment issues etc, I realized that my implementation of g++4.9 (macports OS X) does not have support for std::align. If I try to compile (with -std=c++11) this example code from http://www.cplusplus.com/reference/memory/align/

// align example
#include <iostream>
#include <memory>

int main() {
  char buffer[] = "------------------------";
  void * pt = buffer;
  std::size_t space = sizeof(buffer)-1;
  while ( std::align(alignof(int),sizeof(char),pt,space) ) {
    char* temp = static_cast<char*>(pt);
    *temp='*'; ++temp; space-=sizeof(char);
    pt=temp;
  }
  std::cout << buffer << '\n';
  return 0;
}

编译器吐出来的是错误

the compiler spits out the error

error: 'align' is not a member of 'std'

这似乎很奇怪的G ++似乎因为G ++ 4.8， HTTPS来已经实现对齐支持：//gcc.gnu。组织/项目/ cxx0x.html （N2341）

This seems strange as g++ seems to have implemented alignment support since g++4.8, https://gcc.gnu.org/projects/cxx0x.html (N2341)

在code下铛++没有任何问题汇总。

The code compiles under clang++ without any problems.

这是G ++，我不知道的一个众所周知的问题？在线编译器，我测试过（ideone和coliru）拒绝code也。

Is this a well known issue of g++ that I am not aware of? The online compilers that I tested (ideone and coliru) reject the code also.

推荐答案

是的，这是一个已知的缺失功能的GCC：

Yes, this is a known missing feature for gcc :