} // op_Implicit(optional)
/// <summary>
/// Compares the current object with another object of the same type.
/// <c>None</c> is considered to be less than all <c>Some(value)</c>; if
/// both objects have values, they are compared.
/// </summary>
///
/// <returns>
/// A 32-bit signed integer that indicates the relative order of the
/// objects being compared. The return value has the following
/// meanings: Value Meaning Less than zero This object is less than the
/// <paramref name="other" /> parameter.Zero This object is equal to
/// <paramref name="other" />. Greater than zero This object is greater
/// than <paramref name="other" />.
/// </returns>
///
/// <param name="other">An object to compare with this object.</param>
/// <remarks>Requires that <typeparamref name="T"/> is
/// <see cref="IComparable{T}"/>. Null is considered to be less than
/// <c>None</c>.</remarks>
public int CompareTo(OptionalNotNull <T> other)
{
return(HasValue
? (other.HasValue
? Comparer <T> .Default.Compare(_value, other._value)
: 1)
: (other.HasValue ? -1 : 0));
} // CompareTo(other)
/// <summary>
/// Asserts the value is not null.
/// </summary>
/// <returns><c>Some(Value)</c> if this optional has a value and this value is not
/// <c>null</c>; <c>None</c> if this optional doesn't have a value.</returns>
/// <exception cref="InvalidOperationException">when the value exists and is
/// <c>null</c>.</exception>
public OptionalNotNull <T> AssertNotNull()
{
// ReSharper disable CompareNonConstrainedGenericWithNull
if (HasValue)
{
if (Value == null)
{
throw new InvalidOperationException(
"Value can't be null", new ArgumentNullException("Value"));
}
else
{
return(OptionalNotNull.Some(Value));
}
}
else
{
return(OptionalNotNull.None <T>());
}
// ReSharper restore CompareNonConstrainedGenericWithNull
}
} // op_Inequality(one, other)
///<summary>
///Indicates whether the current object is equal to another object of the same type.
///</summary>
///
///<returns>
///true if the current object is equal to the <paramref name="other" /> parameter; otherwise, false.
///</returns>
///
///<param name="other">An object to compare with this object.</param>
/// <remarks>Requires that <typeparamref name="T"/> is <see cref="IEquatable{T}"/>.</remarks>
public bool Equals(OptionalNotNull <T> other)
{
return(HasValue
? other.HasValue && _value.Equals(other._value)
: !other.HasValue);
} // Equals(other)
} // OrElse(@default)
/// <summary>
/// If this optional has a value, returns itself; else returns
/// <paramref name="@default"/>.
/// </summary>
/// <param name="default">The @default.</param>
/// <returns></returns>
public OptionalNotNull <T> OrElse(OptionalNotNull <T> @default)
{
return(HasValue ? this : @default);
} // OrElse(@default)
