/src/NUnit/framework/Constraints/ReusableConstraint.cs

 1using System;
 2
 3namespace NUnit.Framework.Constraints
 4{
 5    /// <summary>
 6    /// ReusableConstraint wraps a resolved constraint so that it
 7    /// may be saved and reused as needed.
 8    /// </summary>
 9    public class ReusableConstraint : IResolveConstraint
10    {
11        private Constraint constraint;
12
13        /// <summary>
14        /// Construct a ReusableConstraint
15        /// </summary>
16        /// <param name="c">The constraint or expression to be reused</param>
17        public ReusableConstraint(IResolveConstraint c)
18        {
19            this.constraint = c.Resolve();
20        }
21
22        /// <summary>
23        /// Conversion operator from a normal constraint to a ReusableConstraint.
24        /// </summary>
25        /// <param name="c">The original constraint to be wrapped as a ReusableConstraint</param>
26        /// <returns></returns>
27        public static implicit operator ReusableConstraint(Constraint c)
28        {
29            return new ReusableConstraint(c);
30        }
31
32        /// <summary>
33        /// Returns the string representation of the constraint.
34        /// </summary>
35        /// <returns>A string representing the constraint</returns>
36        public override string ToString()
37        {
38            return constraint.ToString();
39        }
40
41        #region IResolveConstraint Members
42
43        /// <summary>
44        /// Resolves the ReusableConstraint by returning the constraint
45        /// that it originally wrapped.
46        /// </summary>
47        /// <returns>A resolved constraint</returns>
48        public Constraint Resolve()
49        {
50            return constraint;
51        }
52
53        #endregion
54    }
55}