Rule 19.12 (# and ## operator) real issue?

[misra-c]

If the macro

Code:

#define m (a,b) a##3##b

is invoked as

Code:

m ( PRE, SUF ) = 0;

then the order of evaluation is important. The result of the ## operator
must be a valid preprocessing token.

Left-to-right evaluation gives 'PRE3' followed by 'PRE3SUF'.

However, the first expansion from right-to-left evaluation is 3SUF, which is
not a valid preprocessing token.