Re: sizeof

On 2022-05-08 11:22, Russell Shaw wrote:
> When inspecting a C++ file, i get:
> 
> (gdb) p sizeof(int())
> $82 = 1
> 
> (gdb) p sizeof(int)
> $83 = 4
> 
> Not right ?
> 
> Package: gdb
> Version: 11.2-1
> on debian

The compiler seems to agree with GDB:

    $ cat test.cpp
    #include <stdio.h>

    int main()
    {
      printf("%zu\n", sizeof(int));
      printf("%zu\n", sizeof(int()));
    }
    $ g++ test.cpp
    test.cpp: In function ‘int main()’:
    test.cpp:6:19: warning: invalid application of ‘sizeof’ to a function type [-Wpointer-arith]
        6 |   printf("%zu\n", sizeof(int()));
          |                   ^~~~~~~~~~~~~
    $ ./a.out
    4
    1

I don't really know what sizeof(int()) means anyway.  clang just rejects
it:

    $ clang++ test.cpp
    test.cpp:6:19: error: invalid application of 'sizeof' to a function type
      printf("%zu\n", sizeof(int()));
                      ^     ~~~~~~~

Simon