Re: undefined compound chaining behavior

[Hossein Sajjadi]

"Except  where  noted,  evaluations  of  operands  of  individual
operators  and  of  subexpressions  of  individual  expressions are
unsequenced.
Given any two evaluations A and B, if A is sequenced before B, then
the execution of A shall precede the execution of B. If A is not
sequenced before      B  and B  is not sequenced before  A, then A and
B  are  unsequenced. [ Note:  The execution of unsequenced evaluations
 can  overlap. — end  note] §1.9"(ISO International Standard ISO/IEC
14882:2011(E) -- Programming Language C++)
For example in expression a + b the standard imposes no requirement if
a evaluated first or b.
so evaluation of expression a=1;a+=a+=4 due to above and other
specifications in §1.9 of standard.

But "the Java programming language guarantees that the operands of
operators appear
to be evaluated in a specific evaluation order , namely, from left to
right.§1.5"(The Java® Language Specification Java SE 8 Edition)
so a=1;a+=a+=4; in Java programming language well defined.

Octave has no standard, so evaluation of expressions can be in any order