Fixes issue #1864. Given the simple set-up:
a --> b --> c
^-----------|
This would translate into an edge based graph (ab) -> (bc),
(bc) -> (ca), (ca) -> (ab).
Starting at the end of the one-way street (ab) and going to
the beginning, the query has to find a self-loop within the
graph (ab) -> (bc) -> (ca) -> (ab), as both nodes map to the
same segment (ab).
Found with
```
daniel@x1c /t/o/i/util> for header in *.hpp
echo -n $header:
ag -iQ $header ../../ --noheading | wc -l
end
...
fixed_point_number.hpp:0
range_algorithms.hpp:0
...
```
Only two. Surprises me to be honest.
But we're cleaning up for quite a bit now.
When you mark free standing functions as `static inline` instead
of just `inline` they can not get merged across TUs and therefore
produce code bloat which is bad for the binaries size, the CPUs
instruction cache, and so on.
Please also see the discussion at:
- https://groups.google.com/forum/#!topic/mozilla.dev.platform/Ulw9HoZbSyQ
- http://stackoverflow.com/a/12836392
Note that non-fully specialized templates (i.e. with a kind of at
least `Template :: * -> *`) are `inline` by default.
