Build index array

Hello,

I'm looking for a PHP function that takes an array of objects 
(associative arrays) and changes the keys to one of the subvalues. You 
probably won't understand this, so I'll give an example.

Here's the source data:

[
   [
     'col1' => 'val1a',
     'col2' => 'val2a',
     'col3' => 'val3a'
   ],
   [
     'col1' => 'val1b',
     'col2' => 'val2b',
     'col3' => 'val3b'
   ],
   [
     'col1' => 'val1c',
     'col2' => 'val2c',
     'col3' => 'val3c'
   ]
]

The desired result for the index key 'col1' is:

[
   'val1a' => [
     'col1' => 'val1a',
     'col2' => 'val2a',
     'col3' => 'val3a'
   ],
   'val1b' => [
     'col1' => 'val1b',
     'col2' => 'val2b',
     'col3' => 'val3b'
   ],
   'val1c' => [
     'col1' => 'val1c',
     'col2' => 'val2c',
     'col3' => 'val3c'
   ]
]

All subarrays are still there (the order doesn't matter) but their keys 
are changed from 0, 1, 2... to the value of their 'col1' entry so I can 
access each subarray quickly and easily (and efficiently?) by its ID or 
name or whatever.

That's similar to .NET LINQ's ToDictionary method that takes a key 
selector delegate and builds exactly this structure. It can be used to 
convert an ordinary database query result to a lookup dictionary.

I know I can write this in a handful of lines of code, but I need this 
on a regular basis so before I roll my own version, I want to make sure 
I haven't missed something that's already there. Preferably for PHP 7.4 
and newer.

-Yves