Challenge 2: Compiling the Same malloc Code as C vs. C++ — Possible Solution
====================================================================

test.c / test.cpp (identical contents):

#include <stdlib.h>

int main() {
    int *nums = malloc(5 * sizeof(int));
    return 0;
}

Compiled as C:

    $ gcc test.c -o test_c
    (compiles successfully, no error or warning)

Compiled as C++ (same file, renamed .cpp, or forced with -x c++):

    $ g++ -x c++ test.c -o test_cpp
    test.c: In function 'int main()':
    test.c:4:16: error: invalid conversion from 'void*' to 'int*' [-fpermissive]
        4 |     int *nums = malloc(5 * sizeof(int));
          |                 ^~~~~~~~~~~~~~~~~~~~~~~~
          |                 |
          |                 void*

Report: the exact same source code compiles cleanly as C but fails to
compile as C++, producing a genuine compile error rather than a
warning -- exactly the chapter's own claim that this specific pattern
is "valid C, invalid C++." The fix, matching the chapter's own
corrected example, is adding an explicit cast: int *nums =
(int *)malloc(5 * sizeof(int));, after which it compiles under g++ as
well.

WHY THIS WORKS AS AN ANSWER
------------------------------
This uses the IDENTICAL source file compiled under both compilers,
showing the C compile succeeding and the C++ compile failing with a
real, specific error message (not just a vague "it breaks"), directly
confirming the chapter's own claim rather than restating it.