C Data Handles

简介

FFI\CData objects can be used in a number of ways as a regular PHP data:

• C data of scalar types can be read and assigned via the $cdata property, e.g. $x = FFI::new('int'); $x->cdata = 42;
• C struct and union fields can be accessed as regular PHP object property, e.g. $cdata->field
• C array elements can be accessed as regular PHP array elements, e.g. $cdata[$offset]
• C arrays can be iterated using foreach statements.
• C arrays can be used as arguments of count().
• C pointers can be dereferenced as arrays, e.g. $cdata[0]
• C pointers can be compared using regular comparison operators (<, <=, ==, !=, >=, >).
• C pointers can be incremented and decremented using regular +/-/ ++/–- operations, e.g. $cdata += 5
• C pointers can be subtracted from another using regular - operations.
• C pointers to functions can be called as a regular PHP closure, e.g. $cdata()
• Any C data can be duplicated using the clone operator, e.g. $cdata2 = clone $cdata;
• Any C data can be visualized using var_dump(), print_r(), etc.

注意: Notable limitations are that FFI\CData instances do not support isset(), empty() and unset(), and that wrapped C structs and unions do not implement Traversable.

类摘要