optionalscalar.hh

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#ifndef DUMUX_COMMON_OPTIONAL_SCALAR_HH
#define DUMUX_COMMON_OPTIONAL_SCALAR_HH
 
#include <limits>
#include <cmath>
 
namespace Dumux {
 
template<class T>
struct OptionalScalar
{
    static_assert(std::numeric_limits<T>::has_quiet_NaN, "T has to be able to represent a quiet NaN!");
 
    OptionalScalar() = default;
 
    OptionalScalar(T value)
    : value_(value)
    {}
 
    T value() const
    { return value_; }
 
    explicit operator bool() const
    {
        using std::isnan;
        return !isnan(value_);
    }
private:
    T value_ = std::numeric_limits<T>::quiet_NaN();
};
 
} // namespace Dumux
 
#endif