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Use when you need enum-to-string serialization without reflection — [StringEnum] source generator produces compile-time ToString(), Parse(), and TryParse() methods that are NativeAOT-safe and zero-allocation.
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Use when representing optional values explicitly — Maybe<T> as a null-safe container, Maybe.From()/FromTry() for creation, HasValue/HasNoValue, Map/Bind chaining, TapNone for None-side effects, Match for consumption, and ToMaybeResult() to bridge into the Result pattern.
Use when handling operation outcomes without exceptions — Result and Result<T> for success/failure, railway-oriented chaining with Then/ThenAsync/Ensure, Match for consumption, and Result.And/Or for combining multiple results.
Use when composing business validation logic — define rules as classes, Func fields, or inline lambdas; combine with .And()/.Or()/.Linear()/.Next(); evaluate with RuleEngine.Evaluate(); branch with RuleEngine.If().
Use when modeling partial success — These<TError, TValue> holds Left (error only), Right (value only), or Both (error + value), enabling scenarios where a result can partially succeed while carrying warnings. Use FromResult to bridge from Result<T>, ToResult/ToResultLenient to bridge back, and Partition to split collections.
Use when you need testable time — IDateTimeProvider wraps clock access so production code uses DateTimeProvider while tests use the built-in FakeDateTimeProvider to freeze/advance/set the clock; also provides .ToDateOnly() and .ToTimeOnly() DateTime extension methods.
Use when adding cross-cutting pipeline behaviors to CQRS handlers — ValidationBehavior (CSharpEssentials.Validation, throws EnhancedValidationException), LoggingBehavior (ILoggableRequest), ExceptionHandlingBehavior (auto-converts exceptions to Result.Failure for Result-returning handlers), CachingBehavior (ICacheable with IDistributedCache), and TransactionScopeBehavior (ITransactionalRequest).
| name | csharpessentials-enums |
| description | Use when you need enum-to-string serialization without reflection — [StringEnum] source generator produces compile-time ToString(), Parse(), and TryParse() methods that are NativeAOT-safe and zero-allocation. |
[StringEnum] is a source generator attribute that produces fast, reflection-free string conversion methods for enum types. Safe for NativeAOT and Blazor WASM.
dotnet add package CSharpEssentials.Enums
using CSharpEssentials.Enums;
[StringEnum]
public enum OrderStatus { Pending, Processing, Shipped, Delivered, Cancelled }
[StringEnum]
public enum UserRole { Admin, Editor, Viewer }
The source generator emits at compile time:
// Generated methods (no reflection, no allocations)
string s = OrderStatus.Shipped.ToStringFast(); // "Shipped"
bool parsed = OrderStatus.TryParse("Shipped", out OrderStatus status);
OrderStatus s = OrderStatus.Parse("Shipped"); // throws on unknown value
ConditionalStringEnumConverter (in CSharpEssentials.Json) serializes [StringEnum]-decorated enums as strings and all others as integers:
// In JsonOptions setup
options.Converters.Add(new ConditionalStringEnumConverter());
// OrderStatus (has [StringEnum]) → "Shipped" in JSON
// HttpMethod (no [StringEnum]) → 2 in JSON
[StringEnum] to any enum that appears in API responses, logs, or database columns as textConditionalStringEnumConverter so string enums serialize naturally in ASP.NET CoreRuntimeReflectionExtensions involved