Examples

Usage

var obj0 = $F(1.0), obj1 = $F(2.0);
var r = $(Box, obj0);
show(r);
show(deref(r)); /* 1.0 */
ref(r, obj1);
show(deref(r)); /* 2.0 */
assign(r, obj0);
show(deref(r)); /* 1.0 */

Lifetimes

var quote = $S("Life is long");

with (r in $B(new(String, quote))) {
  println("This reference is: %$", r);
  println("This string is alive: '%s'", deref(r));
}

print("Now it has been cleared up!\n");

Collection

/* Multiple Types in one Collection */
var x = new(Array, Box, 
  new(String, $S("Hello")), 
  new(String, $S("There")), 
  new(Int, $I(10)));

print(deref(get(x, $I(0)))); /* Hello */

del(x); /* Contents of `x` deleted with it */

Box

Unique Pointer

The Box type is another wrapper around a C pointer with one additional behaviour as compared to Ref. When a Box object is deleted it will also call del on the object it points to. The means a Box is considered a pointer type that owns the object it points to, and so is responsible for it's destruction. Due to this Boxs must point to valid Cello objects and so can't be initalised with NULL or anything else invalid.

While this might not seem that useful when there is Garbage Collection this can be very useful when Garbage Collection is turned off, and when used in conjunction with collections.

Definition

struct Box {
  var val;
};

Derives

Alloc$ alloc dealloc
Castcast
Cmpcmp eq neq gt lt ge le
Copycopy
Hashhash hash_data
Sizesize
Swapswap

Implements

Assignassign
Docname brief description definition
Newnew del construct destruct
Pointerref deref
Showshow look print scan

Back

Cello High Level C

Examples

Box

Definition

Derives

Implements