I agree we should use operator overloading only when it really fits the use case. Especially the function call operator is easily misused.

I don’t completely agree with Raymond Chen here though. Firstly I don’t think providing both an explicit Load() function and the function call operator is the solution. Just keep things simple and obvious: provide Load() and remove the function call operator.

Secondly, why is StorageLoader even a class (or actually a struct here, but we know that’s the same thing in C++)? Unless Raymond is leaving out something essential, there is no state. Just make a function:

template<typename DataType>
LoadFromStorage(StorageOptions<DataType> const* options) {
    // ...
}