Types, Records, and Modern C#

These standards cover how to choose between class, record, and struct; how to model closed sets of variants; and how to use modern C# (records, pattern matching, extension members, collection expressions) to express intent without boilerplate. Apply them whenever defining a new type or deciding how a value should be represented.

• Add Record Factories via Extension Members
• Approximate F# Discriminated Unions With Sealed Records
• Choose class, record, or struct Based on Semantics
• Choose the Right Record Kind by Required Equality and Storage Semantics
• Choose the Right Sum-Type Representation for Closed Sets of Variants
• Closed Shapes, No Nulls: F# Discipline in C#
• Model Discriminated Unions as Sealed Record Hierarchies
• Persist a C# Union Type in EF Core via a Shadow Complex Property
• Prefer Closed Records + Functional Map Over OO Interfaces
• Prefer params IReadOnlyList<T> Over params T[]
• Use C# 14 Extension Members for Context-Specific Views
• Use Modern C# Syntax to Remove Boilerplate
• Use Property Patterns and Tuple Switch Expressions
• Use var by Default
• Validate Records at Construction With a Nullable Factory
• Wrap Measured Quantities in Dedicated Types