I want to compile this code: 

```
#include <stdalign.h>
#include <stdio.h>
#include <stddef.h>
int main ( int argc , char ** argv )
{
    printf ("%zu\n", alignof ( max_align_t ));
    return 0;
}

```

But compiler says that: 

```
error: ‘max_align_t’ undeclared".

```

`stddef.h` is included and everything must be ok, isn't it?

P.S. I already tried to compile this code under gcc4.8 and gcc4.9, but I have error as described.
['https://Stackoverflow.com/questions/33134621', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/5444662/']
To use a C11 feature you need to tell the compiler to run in C11 compliant mode.

For gcc this can be achieved by specifying the option `-std=c11`.
I use a compiler that is natively based on c99 that has a stddef.h that it uses. On my computer I need to use the -std=c11 option and also a header file that apparently corresponds to c11.