Strange behaviour of the pow function

ifelse(T, cut(x, 3), T)

 If ‘X’ is not an array but an object of a class with a non-null
 ‘dim’ value (such as a data frame), ‘apply’ attempts to coerce it
 to an array via ‘as.matrix’ if it is two-dimensional (e.g., a data
 frame) or via ‘as.array’.

parab[] <- lapply(parab, function(x) if(is.numeric(x)) cut(x, 3) else x)

for (int i = 0; i < state_string.length(); i++)
{
    // ...
    cout << state_string.at(i) << "\t" << state_string.at(i + 1) << endl;
}

for (int i = 0; i < state_string.length() - 1; i++)

 warning: conversion to ‘int’ from ‘double’ may alter its value [-Wfloat-conversion]
     double diff = abs(r1-r2);

echo date('Y-m-d', strtotime('April 31'));
// 2018-05-01