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;