I'd change first sentence of the current long and complex explanation of the erase effects:
Iterators and references to the erased elements and to the elements between them and the end of the container are invalidated.
with much shorter and easier to understand as specified in the C++11 standard document:
Invalidates iterators and references at or after the point of the erase.
 Inverted complexity explanation
If I'm right, the complexity description 1) actually refers to the version 2) and viceversa.
188.8.131.52 07:23, 3 August 2014 (PDT) Hernán.