Some PHP benchmarks - Very nice! WoW!
Based on phpbench/phpbench.
composer install
Run all tests
bin/bench benchmarks 
Run specific test
bin/bench benchmarks/GetFirstElementOfArray.php
+-------------------+---------+-------+
| subject           | mean    | diff  |
+-------------------+---------+-------+
| benchWithFirstKey | 0.048μs | 1.00x |
| benchWithCurrent  | 0.060μs | 1.27x |
| benchWithForeach  | 0.065μs | 1.36x |
| benchWithReset    | 0.107μs | 2.25x |
+-------------------+---------+-------+Remove last element of tiny array (10 entries)
+------------------------------------+---------+-------+
| subject                            | mean    | diff  |
+------------------------------------+---------+-------+
| benchWithUnset                     | 0.117μs | 1.00x |
| benchWithArraySlice                | 0.135μs | 1.15x |
| benchWithArrayPop                  | 0.145μs | 1.24x |
| benchWithArrayReverseAndArrayShift | 0.253μs | 2.17x |
+------------------------------------+---------+-------+Remove last element of large array (10000 entries)
+------------------------------------+----------+-------+
| subject                            | mean     | diff  |
+------------------------------------+----------+-------+
| benchWithArrayPop                  | 31.149μs | 1.00x |
| benchWithUnset                     | 32.279μs | 1.04x |
| benchWithArraySlice                | 33.904μs | 1.09x |
| benchWithArrayReverseAndArrayShift | 94.314μs | 3.03x |
+------------------------------------+----------+-------+Create new object (thanks @nicolasbonnici)
+-------------------------------+---------+-------+
| subject                       | mean    | diff  |
+-------------------------------+---------+-------+
| benchWithArrayAndCast         | 0.086μs | 1.00x |
| benchWithAnonymousDeclaration | 0.088μs | 1.02x |
| benchWithJsonEncode           | 0.114μs | 1.32x |
| benchWithSdtClass             | 0.124μs | 1.44x |
+-------------------------------+---------+-------+Licensed under the terms of the MIT License.