Shrub - opposite leaves, tiny white 4-petaled flowers

I decided this was Oleaceae for all the wrong reasons (well, it does have opposite leaves), and now I keep coming up with Osmanthus. Is that what it is? The leaves don't appear stiff enough for Osmanthus fragrans, which is the closest I've seen that's as sparsely flowered. I think the flowers are less than 1cm across, though I didn't measure them.

 

It is Euonymus sp.

 

Ditto to a spindle Euonymus sp., probably Euonymus europaeus.

 

Thank you both! Such teeny flowers. Actually, the petals look more round than on the E. europaeus photos I see. We have a lot of Euonymus alatus (edited - seems to be alatus, not elata) in landscaping here, photos look similar.
Celastraceae.

 

Think you mean Euonymus alatus.
There are no sign of winged twigs...so not sure if that is correct.

euonymus alatus - Google Search

 

This looks promising (?), from a photo I didn't post at first.

 

I went back there. Here we go. So Euonymus alatus.