9.15 Transposition operator
----------------------------
C-- has a transposition operator, which is not found in other
languages. This operator transposes the contents of two variables and is
indicated by ><. The variables must both have the same number of bits -
whether 8, 16, or 32.
A few examples:
AX >< BX; // saves the value of BX in AX and of AX in BX
CH >< BL; // interchanges the contents of registers CH and BL
dog >< cat; /* interchanges the values of variables dog and cat
counter >< CX; // interchanges the values of variable counter and
// register CX
Transposition between two 8-bit variables in memory causes the contents
of register AL to be destroyed. Transposition between two 16-bit variables
in memory causes the contents of AX to be destroyed. Transposition between
two 32-bit variables in memory causes the contents of EAX to be destroyed.
In all other transpositions, such as between a variable in memory and a
register, the values of all registers are saved.