You do have to understand that compiler teams aren't saying something like "this triggers UB, quick just replace it with noop." It's just something that naturally happens when you need to reason about code.
For example, consider a very simple statement.
let array[10];
let i = some_function();
print(array[i]);
The function might not even be known to the compiler at compilation time if it was from a DLL or something.
But the compiler is like "hey! you used the result of this function as an index for this array! i must be in the range [0, 10)! I can use that information!"
For example, consider a very simple statement.
The function might not even be known to the compiler at compilation time if it was from a DLL or something.But the compiler is like "hey! you used the result of this function as an index for this array! i must be in the range [0, 10)! I can use that information!"