# LibBytes

These utility functions provide convenient operations for manipulating byte arrays in Solidity.

### toAddress():

This function is used to convert a portion of a byte array into an `address`. It takes in the byte array (`self`) and a starting index (`start`). It verifies that the byte array has enough bytes to read an address (20 bytes) starting from the specified index. Then, it uses assembly code to load the address from the specified location in memory and returns it.

Input:

<table><thead><tr><th>Field</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">self
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">bytes
</code></pre></td><td>The bytes that contains the address.</td></tr><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">start
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">uint256
</code></pre></td><td>The starting position to retrieve the address from the bytes.</td></tr></tbody></table>

Output:

<table><thead><tr><th>Field</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">tempAddress
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">address
</code></pre></td><td>The retrieved address from the bytes.</td></tr></tbody></table>

### slice():

This function is used to extract a slice of bytes from a byte array. It takes in the byte array (`self`), a starting index (`start`), and a length (`length`). It checks that the specified slice is within the bounds of the byte array. Then, it creates a new byte array (`tempBytes`) with a length equal to the specified slice length. It uses assembly code to copy the slice from the original byte array to the new byte array. Finally, it updates the length of the new byte array and returns it.

Input:

<table><thead><tr><th>Field</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">self
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">bytes
</code></pre></td><td>The string of bytes that needs to be sliced</td></tr><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">start
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">uint256
</code></pre></td><td>The starting position to begin slicing</td></tr><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">length
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">uint256
</code></pre></td><td>The length of the byte</td></tr></tbody></table>

Output:

<table><thead><tr><th>Field</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">tempBytes
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">bytes
</code></pre></td><td>The sliced byte</td></tr></tbody></table>

### concat():

This function is used to concatenate two byte arrays. It takes in two byte arrays (`self` and `postBytes`). It creates a new byte array (`tempBytes`) with a length equal to the combined lengths of the two input byte arrays. It uses assembly code to copy the contents of the two byte arrays into the new byte array. Finally, it updates the length of the new byte array and returns it.

Input:

<table><thead><tr><th>Field</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">self
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">bytes
</code></pre></td><td>The bytes that needs to be concatenated.</td></tr><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">postBytes
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">bytes
</code></pre></td><td>The bytes that needs to be concatenated.</td></tr></tbody></table>

Output:

<table><thead><tr><th>Field</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">tempBytes
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">bytes
</code></pre></td><td>The concatenated bytes</td></tr></tbody></table>