C++ accessors for value instances are not "const".
The accessor functions for type fields are marked `const`, e.g.:
```cpp
    public:
        double val_in_rads() const { return m_val_in_rads; }
```
but the accessor for the related instance is not:
```cpp
    public:
        double val_in_degrees();
```
```cpp
double mystruct_t::loc_status_t::val_in_degrees() {
    if (f_val_in_degrees)
        return m_val_in_degrees;
    m_val_in_degrees = ((val_in_rads() * 180.0) / 3.14159265);
    f_val_in_degrees = true;
    return m_val_in_degrees;
}
```
Is this intentional?

It's annoying, because my higher level code doesn't distinguish between the two types of accessor functions (and, because the higher level code receives a pointer-to-const parameter, so it can't call the instance accessor function without casting away the `const`, which is _ugly_).

Thanks!