Money data type for .NET?

Question

Looking for a good Money data type for .NET that supports currencies and exchange rates (with related behaviour & operations).

• Note: I started searching for the source code seen in print in the book Test-Driven Development By Example by author Kent Beck - he develops a nice Monetary concept. Unable to find the complete source online. The book does not contain one singular listing - instead it develops the source code over the duration of the book.

Although the book doesn't go deeper I would also like the Money class to support different rounding mechanisms because that also varies among financial institutions around the globe.

Edit 1: Clarifications

By "Money class" I mean a .NET data type that I can use to support money and its operations, complete with currency support and exchange rate calculations. Something like that is a higher level abstraction and might internally use a primitive data type. Also it might rely on a bundle of classes like: Money, ExchangeRate, Bank, etc.

It might be a value type (i.e. struct) or reference type (i.e. class) but either way it would be complete and support the aforementioned features.

Edit 2: Objectives of Money data type

(This also shows why a raw decimal, int or other primitive type won't suffice for all Money needs)

Objectives of a Money data type would be:

• Safety features (i.e. prevent arithmetic on different currency types).
• Store the currency type with the value (i.e. AUD, US, DKK).
• Store formatting details (i.e. decimal grouping, currency symbols, etc.).
• Conversion providers (e.g. exchange rate) to help round out the solution.
• Reduce multiple currencies in an expression to achieve a result.

Note: Varying data values like exchange rates can be loaded from an external source and used. This question does not infer anything dynamic is hard-coded into the concept of Money.

Answer 1

I am the author of NMoneys which I think it might come handly. It has not been "officially released" yet, but it will change very little until it does.

Answer 2

I do understand your points about the benefit of having abstraction layer over money here. However, my view on money and its "operations" is quite blurry. For other things like File, it's clear to me there should be Open, Read, Write, Close operations. But for Money, I can't think of much other than basic math operations (+,-,*,/)

One of C++ quantitative finance lib I know does contain this Money abstraction (http://quantlib.org/reference/class_quant_lib_1_1_money.html.) But you can clearly see that this is a very thin wrapper which provide basic operator overloads and unit conversion over Decimal.

In most cases, I think decimal can fulfill your requirement. If there is specific Money operation you need to support, I think it's okay to roll out your own classes.