NH-3964 - obsolete Linq.ReflectionHelper in favor of Util.ReflectHelper.

[fredericDelaporte]

Follow up of NH-3964 and its first PR #574 .

Methods are just moved to ReflectHelper, without changing them.

Trying to use

public static MethodInfo GetMethod<T, TResult>(Func<T, TResult> func, T arg1)
{
return func.Method;
}

is requiring as many overloads as function arguments counts

public static MethodInfo GetMethod<T1, T2, TResult>(Func<T1, T2, TResult> func, T1 arg1, T2 arg2)
{
    return func.Method;
}

Then type inference is sometime inferior:

return GetMethod(Enumerable.GroupBy, (IEnumerable<int>)null, (Func<int, decimal>)null);

Instead of

return GetMethod(() => Enumerable.GroupBy(null, (Func<int, decimal>)null));

And handling instance methods are requiring a Func<Func<>> with a non-null instance:

public static MethodInfo GetMethod<TSource, T1, TResult>(Func<TSource, Func<T1, TResult>> func, TSource source, T1 arg1)
{
	return func(source).Method;
}

GetMethod<string, int, string>(s => s.Substring, "", 10);

So well, even though some "brute force" runtime performance comparison show it is "better", I do not think it is worth all the required changes and additional code for using them.

[hazzik]

• We need about 4 overloads for GetMethodInfo & 4 overloads for GetMethodDefinition, it's true.
• There are only few cases where we do not have an instance upfront. For string we can use string.Empty and for structs default(T) (where T is a struct). Where we need a real instance we can use the old method.
• (IEnumerable<int>)null looks clearer as default(IEnumerable<int>)

[fredericDelaporte]

Snapshot dependency failure for failed build: looks like a Team City infrastructure failure, doesn't it? I should probably trigger a later rebuild with a rebase.

[fredericDelaporte]

Well, search&replace does not make it for this obsolete reason. I would fix it tomorrow for triggering another build by the way.

[fredericDelaporte]

Amended for updating a doc example referencing ReflectionHelper, and rebased.

[fredericDelaporte]

Found two additional method reflection which are cacheable and were not. Now cached. And rebased.

[hazzik]

LGTM