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Diffstat (limited to 'doc/documentation.tex')
| -rw-r--r-- | doc/documentation.tex | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/doc/documentation.tex b/doc/documentation.tex index 349de9b..d6adc5d 100644 --- a/doc/documentation.tex +++ b/doc/documentation.tex @@ -199,9 +199,12 @@ bitmask corresponding to the given type or state. For example, if a given type uses three bits of the mask, the returned value could be the integer corresponding to the bitfield $001110000$\ldots, where the location of $1$s indicates the bits which have been allocated to the -given type. A return value of $0$ indicates that the bitmask could +given type. A return value of $-1$ indicates that the bitmask could not be determined for some reason (for example, the requested state -was not previously registered). +was not previously registered)\footnote{Note that a potential +ambiguity arises here, in that if the full mask is allocated to a +single type, then $-1$ is a valid state. It is assumed that this +eventuality won't arise in practice.}. The following macros have been defined for fast setting and checking of the mask by direct bitwise operations: |