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    <p>Even though both methods allocates dynamic memory, one is an object made for handling data of arbitrary length (<code>std::vector&lt;T&gt;</code>), while the other is just a pointer to a sequential line of memory slots of size <code>N</code> (<code>int</code>s in this case).</p> <hr> <p><strong>Among other differences</strong></p> <ul> <li><p>A <code>std::vector&lt;T&gt;</code> will automatically resize the allocated memory for your data if you try to append a new value and it runs out of space. A <code>int *</code> will not.</p></li> <li><p>A <code>std::vector&lt;T&gt;</code> will free the allocated memory when the vector goes out of scope, a <code>int *</code> will not.</p></li> <li><p>A <code>int *</code> will have little to no overhead (compared to the vector), though <code>std::vector&lt;T&gt;</code> isn't exactly a new thing and is normally very optimized. Your bottle neck will probably be elsewhere. </p> <p>But a <code>std::vector&lt;int&gt;</code> will always consume more memory than a <code>int *</code>, and some operations will always take a little more time.</p> <p>So if there are memory/CPU limitations and you want to shave off every single cycle that you possible can.. use an <code>int *</code>.</p></li> </ul> <hr> <p><strong>There are situations where one is definitely preferable over the other!</strong></p> <ul> <li><p>When you need "raw"/"real" memory and <strong>full control</strong> over it, <code>operator new</code> is your best bet. </p> <p>For example when you are using <a href="http://www.parashift.com/c++-faq-lite/dtors.html#faq-11.10" rel="nofollow"><code>placement new</code></a>.</p> <p><sup><em>by raw/real memory I mean something that is not managed through a wrapper-container, such as <code>std::vector&lt;T&gt;</code>.</em></sup></p></li> <li><p>When you are looking for a container to handle arbitrary and don't want to reinvent the wheel regarding memory management; <code>std::vector&lt;T&gt;</code> (or any other appropriate STL container) </p></li> </ul>
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    1. POnew int[size] vs std::vector
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    1. USFilip Roséen - refp
    1. USFilip Roséen - refp
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    1. COIf you need "raw" memory and full control over it, you should be using the `::operator new(size_t)` function, not the `new` operator.
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      1. USJames Kanze
    2. CO@JamesKanze I wrote "raw" (including the quotations) to bring a wider sense to the word, but I guess a little rephrasing wouldn't harm anyone. DONE.
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      1. USFilip Roséen - refp
    3. COOK. The mention of placement new is a good point. Using `new (something) int[size]` is probably a lot easier than writing a custom allocator for `std::vector`.
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