a string or a callable
the name of the first parameter if fun is a string. Defaults to "a".
the name of the second parameter if fun is a string. Defaults to "b".
If fun is not a string, binaryFun aliases itself away to fun.
alias less = binaryFun!("a < b"); assert(less(1, 2) && !less(2, 1)); alias greater = binaryFun!("a > b"); assert(!greater("1", "2") && greater("2", "1"));
Transforms a string representing an expression into a binary function. The string must either use symbol names a and b as the parameters or provide the symbols via the parm1Name and parm2Name arguments.