Let's assume we have a C struct:
typedef struct _Z3_ast *Z3_ast;
and we want to create an array:
Z3_ast args[2];
and assign values:
args[1] = x;
args[1] = y;
The PHP FFI equivalent would be:
<?php
$ffi = FFI::cdef(...
// Create Z3_ast[2] type
$arg_type = FFI::arrayType($ffi->type('Z3_ast'), [2]);
// Create array of type Z3_ast[2]
$args = FFI::new($arg_type);
// Populate the array
$args[0] = $x;
$args[1] = $y;
?>