lambda可以有外部“C”链接吗？

Question

这似乎适用于我尝试过的平台：

#include <iostream>

// extern "C" linkage
extern "C" void foo(void (*fn_ptr)(int));

namespace {
  struct bar {
    static void f(int);
  };
}

int main() {
  // Usually works on most platforms, not guaranteed though:
  foo(bar::f);

  // Probably equally bad or worse?
  foo([](int x) { std::cout << x << std::endl; });
}

但又是passing a static member function also worked on these platforms when it was not required to。

有没有办法强制lambda具有合适的连接以使其安全和便携？或者它已经是？

Answer 1

没有。 Lambda最终是具有函数调用运算符的对象。无捕获的lambda可以转换为适当类型的函数指针，但该函数指针将是带有C ++链接的C ++函数。