Consider capturing constructor variables in the "finally" block

[ggleyzer]

Quite often, there is some computation in the constructor that has to be duplicated in the "finally" block. For example, HasherMap constructor has the following:

construct(Hasher<Key> hasher, Map<Key, Value> that)
    {
    if (that.is(HasherMap) && hasher == that.hasher)
        {
        // optimization:
        construct HasherMap(that);
        }
    else
        {
        construct HasherMap(hasher, that.size);
        }
    }
finally
    {
    if (!(that.is(HasherMap) && hasher == that.hasher))
        {
        putAll(that);
        }
    }

With the capture, we could avoid the code duplication:

construct(Hasher<Key> hasher, Map<Key, Value> that)
    {
    Boolean optimized = that.is(HasherMap) && hasher == that.hasher;
    if (optimized)
        {
        construct HasherMap(that);
        }
    else
        {
        construct HasherMap(hasher, that.size);
        }
    }
finally
    {
    if (!optimized)
        {
        putAll(that);
        }
    }