for (size_t i = 0; i < 100; i++) calculate_something_and_display(i);

How many lines of code does your system show for this?

for (size_t i = 0; i < 100; i++)
{
     calculate_something_and_display(i);
}

How many lines of code does it show for this?

for (size_t i = 0; 
     i < 100; 
     i++)
{
     calculate_something_and_display(i);
}

What about this?

for (size_t i = 0; i < 100; i++)
     calculate_something_and_display(i);

And this?

These are all identical in any meaningful way. The compiler's parser will see them all as exactly the same sequence of tokens with no difference.

And now you can understand perhaps why cloc's complexity isn't entirely "unnecessary"…