git grep -h -B1 "^#\s*pragma once" | grep -v pragma | sort | uniq is now clean. [SVN r85952]
[SVN r78860]
[SVN r64120]
This is motivated by the need to correct the istream_range, to correct the adaptors.hpp header file, and correct the return types of various range algorithms. [SVN r61517]
[SVN r60897]
