how to fix the error: ‘::max_align_t’?

Question

I get the error

"/usr/include/c++/5/cstddef:51:11: error: ‘::max_align_t’ has not been declared using ::max_align_t; ^"

So I should update the libraries because I find this solution:

"A workaround until libraries get updated is to include <cstddef> or <stddef.h> before any headers from that library."
I wrote some command on the Ubuntu terminal such as:

bash $ sudo apt-get install apt-file
bash $ sudo apt-file update
bash $ apt-file search stddef.h

Then still the error exist. Thank you

Answer 1

In the .cpp file where this compile error occurs you need to add

#include <cstddef>

before any of the other headers, e.g.

main.cpp (broken)

#include <cstdio>

int main()
{
    using ::max_align_t;
    puts("Hello World");
    return 0;
}

Try to compile that:

$ g++ -std=c++11 -o test main.cpp
main.cpp: In function ‘int main()’:
main.cpp:5:10: error: ‘::max_align_t’ has not been declared
  using ::max_align_t;
      ^

Then fix it:

main.cpp (fixed)

#include <cstddef>
#include <cstdio>

int main()
{
    using ::max_align_t;
    puts("Hello World");
    return 0;
}

Compile and run it:

$ g++ -std=c++11 -o test main.cpp
$ ./test
Hello World