Validator

Purpose

Legacy guard helpers implemented in Validator.cs. These extension methods provide succinct guard/check semantics but are marked [Obsolete] in source. They throw exceptions when conditions or predicates fail.

When to Use

Prefer modern guard patterns in new code (e.g., ArgumentNullException.ThrowIfNull, ArgumentException, Debug.Assert). Use these only for compatibility with existing code that relies on them.

API

• void Check(this bool condition, string message = null) — Throws InvalidOperationException when condition is false.
• void Check<TException>(this bool condition, string message = null) where TException : Exception, new() — Throws TException (attempts to construct with message first, falls back to default ctor and then InvalidOperationException).
• void Check(this Func<bool> predicate, string message = null) — Throws InvalidOperationException when predicate returns false.
• void Check<TException>(this Func<bool> predicate, string message = null) where TException : Exception, new() — Throws typed exception when predicate fails.

Examples

Validator.Check(value != null, "value required");
Validator.Check<ArgumentNullException>(value != null, "value cannot be null");
Validator.Check(() => value > 0, "must be positive");

Remarks

• These helpers are maintained for legacy compatibility and are intentionally marked [Obsolete] to encourage modern alternatives.
• Check<TException> uses Activator.CreateInstance(typeof(TException), message) when possible; if that fails it falls back to new TException() and finally an InvalidOperationException with the message.