Bump to v4.0.0.

internal/charsStartIndex.js

@@ -0,0 +1,20 @@
+var baseIndexOf = require('./baseIndexOf');
+
+/**
+ * Used by `_.trim` and `_.trimStart` to get the index of the first string symbol
+ * that is not found in the character symbols.
+ *
+ * @private
+ * @param {Array} strSymbols The string symbols to inspect.
+ * @param {Array} chrSymbols The character symbols to find.
+ * @returns {number} Returns the index of the first unmatched string symbol.
+ */
+function charsStartIndex(strSymbols, chrSymbols) {
+  var index = -1,
+      length = strSymbols.length;
+
+  while (++index < length && baseIndexOf(chrSymbols, strSymbols[index], 0) > -1) {}
+  return index;
+}
+
+module.exports = charsStartIndex;