old style assignment

[linuxdude]

I was indenting some code with a program called indent. I accidently indented one of my own codes I wrote, but it gave me this warning.

indent: test.c:8: Warning:old style assignment ambiguity in "=-".  Assuming "= -"

the code was

GLint mov=-8;

What is ambiguous?

[Thantos]

without seeing the actual code line it would be hard to see why. I would venture to guess it wants a space between = and - to avoide confusion between -=1 and =-1 (example).

[linuxdude]

that is what I though. I just thought that it wouldn't really be confused with -=.

[Thantos]

well lint is pretty anal retentive

[swoopy]

I think =- used to be the same as -=, so with under the old style
mov=-8; could mean either:

mov = -8;
Or:
mov = mov - 8;

[Prelude]

>What is ambiguous?
Wow, that's an old warning. Back in the dark ages when the compound assignment operator was added to C, it began with the = and ended with the operation being performed, =- instead of -=, etc... But this caused plenty of confusion because many programmers feared spacing between operators and expected (for some odd reason) things such as v=*p; and x=-y to assign the value pointed to by p to the varible v and the negated value of y to be assigned to x, respectively. The former would try to multiply v by p and the latter would subtract y from x. In light of the surprises, the compound assignment operators were reversed to begin with the operation and end with the = so that these styles wouldn't break the meaning of the code.

But this was some time ago, and I don't know of any compiler today that could possibly parse move=-8 incorrectly.

[chrismiceli]

It wasn't a compiler, it was a program that automatically indents:
http://www.gnu.org/software/indent/indent.html