.NET Guard Class Library?

Question

I\'m looking for a library or source code that provides guard methods such as checking for null arguments. Obviously this is rather simple to build, but I\'m wondering if th

Answer 1

There is CuttingEdge.Conditions. Usage example from the page:

public ICollection GetData(Nullable id, string xml, ICollection col)
{
    // Check all preconditions:
    id.Requires("id")
        .IsNotNull()          // throws ArgumentNullException on failure
        .IsInRange(1, 999)    // ArgumentOutOfRangeException on failure
        .IsNotEqualTo(128);   // throws ArgumentException on failure

    xml.Requires("xml")
        .StartsWith("") // throws ArgumentException on failure
        .EndsWith(""); // throws ArgumentException on failure

    col.Requires("col")
        .IsNotNull()          // throws ArgumentNullException on failure
        .IsEmpty();           // throws ArgumentException on failure

    // Do some work

    // Example: Call a method that should not return null
    object result = BuildResults(xml, col);

    // Check all postconditions:
    result.Ensures("result")
        .IsOfType(typeof(ICollection)); // throws PostconditionException on failure

    return (ICollection)result;
}

Another nice approach, which isn't packaged in a library, but could easily be, on Paint.Net blog:

public static void Copy(T[] dst, long dstOffset, T[] src, long srcOffset, long length)
{
    Validate.Begin()
            .IsNotNull(dst, "dst")
            .IsNotNull(src, "src")
            .Check()
            .IsPositive(length)
            .IsIndexInRange(dst, dstOffset, "dstOffset")
            .IsIndexInRange(dst, dstOffset + length, "dstOffset + length")
            .IsIndexInRange(src, srcOffset, "srcOffset")
            .IsIndexInRange(src, srcOffset + length, "srcOffset + length")
            .Check();

    for (int di = dstOffset; di < dstOffset + length; ++di)
        dst[di] = src[di - dstOffset + srcOffset];
}

I use it in my project and you could borrow the code from there.