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use libc::size_t;
use std::mem;
use types::{c_long, InternalValue, RBasic, Value};
extern "C" {
pub fn rb_ary_entry(array: Value, offset: c_long) -> Value;
pub fn rb_ary_join(array: Value, separator: Value) -> Value;
pub fn rb_ary_new() -> Value;
pub fn rb_ary_push(array: Value, item: Value) -> Value;
pub fn rb_ary_store(array: Value, index: c_long, item: Value) -> Value;
}
const FL_USHIFT: isize = 12;
const FL_USER_1: isize = 1 << (FL_USHIFT + 1);
const FL_USER_3: isize = 1 << (FL_USHIFT + 3);
const FL_USER_4: isize = 1 << (FL_USHIFT + 4);
#[repr(C)]
enum RArrayEmbed {
LenMask = FL_USER_4 | FL_USER_3,
Flag = FL_USER_1,
LenShift = FL_USHIFT + 3,
}
#[repr(C)]
struct RArrayAs {
heap: RArrayHeap,
}
#[repr(C)]
struct RArrayHeap {
len: c_long,
value: InternalValue,
ptr: InternalValue,
}
#[repr(C)]
struct RArray {
basic: RBasic,
as_: RArrayAs,
}
pub fn rb_ary_len(value: Value) -> c_long {
unsafe {
let basic: *const RBasic = mem::transmute(value.value);
let flags = (*basic).flags;
if flags & (RArrayEmbed::Flag as size_t) == 0 {
let array: *const RArray = mem::transmute(value.value);
(*array).as_.heap.len
} else {
((flags as i64 >> RArrayEmbed::LenShift as i64) &
(RArrayEmbed::LenMask as i64 >> RArrayEmbed::LenShift as i64)) as c_long
}
}
}