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copied!<pre><code>template <typename T> </code></pre> <p>Does this really need to be parameterized? It would seem that any shift quantity can be stored in a <code>size_t</code>, and converting to <code>size_t</code> implicitly or explicitly would be a good idea before starting the rest of the process.</p> <pre><code>integer operator<<(T shift){ </code></pre> <p>Usually binary <code>operator</code> functions are best implemented as non-member <code>friend</code>s. For example, fewer conversions are considered when producing the <code>this</code> pointer than for generic operands. I'd write <code>friend integer operator<< ( integer lhs, size_t shift )</code>.</p> <pre><code> std::list <uint8_t> out = value; </code></pre> <p>If you use a <code>friend</code> and pass-by-value, then this copy is made implicitly. The compiler also has an easier time eliminating it if you are really just modifying one object, e.g. <code>q = q << 3</code>.</p> <pre><code> for(unsigned int i = 0; i < (shift >> 3); i++)// get rid of bytes if shift > 8 </code></pre> <p>Be careful in the loop condition. You're applying an operator to a high-level type, which might cause an expensive computation (or even endless recursion if <code>T</code> is <code>integer</code>!</p> <pre><code> shift &= 7; // shift by less than a byte </code></pre> <p>At this point, if <code>shift == 0</code> you are done. Best to insert a conditional <code>return</code> here. Also, now the range is <em>really</em> limited, so assign to a narrower type than <code>T</code>.</p> <pre><code> out.push_front(0); // extra byte for overflow </code></pre> <p>This is only necessary if the byte will be nonzero. Probably best to special-case the first operation and make the <code>push_front</code> conditional, instead of special-casing the last.</p> <p>… Hmm, it looks like the <code>operator>></code> is being exercised more… skipping to that…</p> <pre><code> for(; i != j; i++){ i++; uint8_t temp = *i << (8 - shift); i--; *i += temp; } *j >>= shift; </code></pre> <p>Clearly the <code>>></code> operator is missing from the loop. Try <code>*i = *i >> shift + temp</code>. Also, I don't see how the list ever gets shorter. Is that done in <code>integer::integer( list<…> )</code>?</p> <p>However, I can't really see what produces the behavior in the posted output. The leading zero is probably a result of the unconditional <code>push_front</code> in <code>operator<<</code>, but the pattern I'd expect is <code>c</code>, <code>6</code>, <code>3</code>, <code>18</code>, <code>c</code>, …. You don't seem to be repeating any sequence, but instead jump randomly.</p> <p>Maybe the division code, or the class constructor could provide clues.</p>

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