clang-tidy - misc-misplaced-const — Extra Clang Tools 18.1.8 documentation

# Extra Clang Tools 18.1.8 documentation

## clang-tidy - misc-misplaced-const

# misc-misplaced-const

This check diagnoses when a `const` qualifier is applied to a `typedef`/ `using` to a pointer type rather than to the pointee, because such constructs are often misleading to developers because the `const` applies to the pointer rather than the pointee.

For instance, in the following code, the resulting type is `int * const` rather than `const int *`:

    typedef int *int_ptr;
    void f(const int_ptr ptr) {
      *ptr = 0; // potentially quite unexpectedly the int can be modified here
      ptr = 0; // does not compile
    }

The check does not diagnose when the underlying `typedef`/`using` type is a pointer to a `const` type or a function pointer type. This is because the `const` qualifier is less likely to be mistaken because it would be redundant (or disallowed) on the underlying pointee type.