    Linear.
          </p>
<h7><a name="json.ref.boost__json__string.find_first_not_of.overload2.h3"></a>
            <span class="phrase"><a name="json.ref.boost__json__string.find_first_not_of.overload2.return_value"></a></span><a class="link" href="overload2.html#json.ref.boost__json__string.find_first_not_of.overload2.return_value">Return
            Value</a>
          </h7><p>
            The first occurrence of a character that is not equal to <code class="computeroutput"><span class="identifier">ch<