Missing Contracts in 1.2.20903.10

Question

Hi,
If String.Contains returns true, then the result from string.LastIndexOf must be >= 0

Answer 1

While this is true, there are a huge number of such "axioms" that capture the relationship between different methods (and note that they can/should span multiple classes/interfaces too). We are searching for a good way to capture such information, but until then would prefer to not include such things in the reference assemblies.

Answer 2

Right. Expressing such contracts would be useful for Equals/GetHashCode/CompareTo. Like a pex test that makes an assertion about symmetry for equals.