I found the answer - with my best tool - Google
C maximum statement length
Now how hard was that?
Having found the answer, I think that my original answer is more important.
Do you have a compiler error? If so, there is probably a much bigger problem.
I have googled that and got no real answer, so I started the thread.
18.104.22.168 Translation limits
1 The implementation shall be able to translate and execute at least one
program that contains at least one instance of every one of the following limits
— 4095 characters in a logical source line
From the C++ Standard
Annex B (informative)
Implementation quantities [implimits]
1 Because computers are finite, C++ implementations are inevitably limited in
the size of the programs they can successfully process. Every implementation
shall document those limitations where known. This documentation may cite
fixed limits where they exist, say how to compute variable limits as a function
of available resources, or say that fixed limits do not exist or are unknown.
2 The limits may constrain quantities that include those described below or
others. The bracketed number following each quantity is recommended as the
minimum for that quantity. However, these quantities are only guidelines and
do not determine compliance.
— Characters in one logical source line [65 536].
So in C++ you can write a program horizontally in one long line.:)