Overview of Constructors and Destructors

Constructors establish a value's initial state. Destructors release resources when that value's lifetime ends. Quxlang declares them as reserved structure members named .CONSTRUCTOR and .DESTRUCTOR.

Named-argument construction

::point STRUCT
{
  .x VAR I32;
  .y VAR I32;

  .CONSTRUCTOR FUNCTION(@x I32, @y I32)
  {
    .x := x;
    .y := y;
  }
}

VAR location point :(@x 3, @y 4);

Constructor calls follow the ordinary named-argument rules. A constructor can also declare positional % parameters when position is deliberately part of the interface.

Field initialization delegates

A :> delegate supplies constructor arguments for a field:

::owner STRUCT
{
  .member VAR point;

  .CONSTRUCTOR FUNCTION(@x I32, @y I32) :> .member:(@x x, @y y)
  {
  }
}

Delegated fields are constructed before the constructor body. Other fields use their applicable default construction.

Inheritance uses the same delegate list for base subobjects. A named base uses its selector, and virtual bases are owned by a complete VIRTUAL_POLYMORPHIC object. See Inheritance for ordinary base delegates and the full-object/subobject constructor forms used with virtual inheritance.

Resource release

.DESTRUCTOR FUNCTION()
{
  IF (.allocation??)
  {
    release(@allocation .allocation);
  }
}

Local values are destroyed automatically at the end of their lifetime. Quxlang also generates eligible default, copy, and move operations; structure modifiers and explicit declarations can suppress or replace them.

Conversion constructors use reserved parameters such as @OTHER, @CHECKED, or @REINTERPRET. See Conversions.

Reference

See the Constructors and Destructors Reference for positional forms, delegates, conversion categories, implicit special operations, array destruction, and control-flow restrictions. Inheritance construction and destruction rules are specified separately in the Inheritance Reference.