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#pragma once
namespace storm {
/**
* Custom Maybe-type for interoperability with C++. It is only intended for value types, and
* aimed at compatibility between C++ and Storm as parameters and return values. As such, a
* number of limitations apply. The preprocessor will warn about most of these.
* - This class can *only* be used with value types. Use MAYBE(X *) for class-types.
* - Classes that rely on custom constructors/destructors are not properly handled
* (they will be created/destroyed even if the data is not present).
* - Classes without a default constructor are not supported (for the above reason).
*/
template <class T>
class Maybe {
public:
// Create an empty value.
Maybe() : data(), present(false) {}
// Create a value.
explicit Maybe(const T &data) : data(data), present(true) {}
// Any value?
inline Bool any() const {
return present;
}
inline Bool empty() const {
return !present;
}
// Get the value. Will not check whether or not the value is present.
T &value() { return data; }
const T &value() const { return data; }
private:
// The actual data.
T data;
// If there is a value present or not.
Bool present;
};
}
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